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Many local chicken breeds are rapidly declining and even facing extinction due to a variety of factors such as indiscriminate crossbreeding, climate fluctuations, epidemic outbreak, and environmental changes. Developing effective preservation strategies is important to address this situation. The special reproductive characteristics and gamete morphology of chickens pose challenges for preserving genetic heritage through the cryopreservation of genetic materials. Currently, gonad and primordial germ-cell cryopreservation and transplantation are the most promising approaches, especially for the genetic information in the W chromosome of female birds. The study of establishing sterile recipients is crucial for increasing the efficiency of the colonization of transplanted donor tissues and cells. Several classical methods, including ovariectomy and testectomy, busulfan, and irradiation, have been employed to deplete endogenous germ cells in recipient males before transplantation. These methods rely on the toxicity of chemical reagents and physical stimulation to kill germ cells. Recent advances in gene-editing technology have introduced sterile hosts via the knocking out of genes relevant to germ cells' development. This review explores state-of-the-art technologies for preparing infertile avian recipients (mainly chickens) and aims to provide guidance for the conservation of poultry genetic material and breed restoration. [ABSTRACT FROM AUTHOR]

Aluminum toxicity poses a significant constraint on crop production in acidic soils. While phytohormones are recognized for their pivotal role in mediating plant responses to aluminum stress, the specific involvement of gibberellin (GA) in regulating aluminum tolerance remains unexplored. In this study, we demonstrate that external GA exacerbates the inhibitory impact of aluminum stress on root growth of rice seedlings, concurrently promoting reactive oxygen species (ROS) accumulation. Furthermore, rice plants overexpressing the GA synthesis gene SD1 exhibit enhanced sensitivity to aluminum stress. In contrast, the slr1 gain-of-function mutant, characterized by impeded GA signaling, displays enhanced tolerance to aluminum stress, suggesting the negative regulatory role of GA in rice resistance to aluminum-induced toxicity. We also reveal that GA application suppresses the expression of crucial aluminum tolerance genes in rice, including Al resistance transcription factor 1 (ART1), Nramp aluminum transporter 1 (OsNramp4), and Sensitive to Aluminum 1 (SAL1). Conversely, the slr1 mutant exhibits up-regulated expression of these genes compared to the wild type. In summary, our results shed light on the inhibitory effect of GA in rice resistance to aluminum stress, contributing to a theoretical foundation for unraveling the intricate mechanisms of plant hormones in regulating aluminum tolerance. [ABSTRACT FROM AUTHOR]

Simple Summary: Pigeons are altricial birds; this means that their newly hatched squabs are characterized by closed eyes, little or no plumage, and undeveloped locomotion organs. Pigeon squabs are unable to feed independently and require parental care, especially feeding with pigeon milk in a mouth-to-mouth manner, if they are to survive. The composition of pigeon milk thus plays an important role in the growth of squabs. The results of this study suggest that supplementing the drinking water of parental pigeons with Enterococcus faecium and Bacillus subtilis increases immunoglobulin levels in pigeon milk. These results provide new insights into the application of probiotics in pigeon production. Enterococcus faecium (E. faecium) and Bacillus subtilis (B. subtilis) are widely used as probiotics to improve performance in animal production, but there have been few reports of their impacts on pigeon milk. In this study, twenty-four pairs of parental pigeons were randomly divided into four groups, with six replicates, and each pair feeding three squabs. The control group drank normal water. The E. faecium group, B. subtilis group, and mixed group drank water supplemented with 3 × 106 CFU/mL E. faecium, 2 × 107 CFU/mL B. subtilis, and a mixture of these two probiotics, respectively. The experiment lasted 19 days. The results demonstrated that the IgA and IgG levels were significantly higher in the milk of Group D pigeons than in the other groups. At the phylum level, Fimicutes, Actinobacteria, and Bacteroidetes were the three main phyla identified. At the genus level, Lactobacillus, Bifidobacterium, Veillonella, and Enterococcus were the four main genera identified. In conclusion, drinking water supplemented with E. faecium and B. subtilis could improve immunoglobulin levels in pigeon milk, and this could increase the ability of squabs to resist disease. E. faecium and B. subtilis could be used as probiotics in the pigeon industry. [ABSTRACT FROM AUTHOR]

Trichomonas gallinae (T. gallinae) has a great influence on the pigeon industry. Pigeons display different resistance abilities to T. gallinae, so the study of the molecular mechanism of resistance is necessary in breeding disease resistant lines. MiRNA plays important roles in the immune response, but there are still no reports of miRNA regulating trichomonosis resistance. We used small RNA sequencing technology to characterize miRNA profiles in different groups. T. gallinae was nasally inoculated in one day old squabs, and according to the infection status, the groups were divided into control (C), susceptible (S) and tolerant (T) groups. We identified 2429 miRNAs in total, including 1162 known miRNAs and 1267 new miRNAs. In a comparison among the C, S and T groups, the target genes of differentially expressed miRNAs were analyzed via GO and KEGG annotation. The results showed that the target genes were enriched in immune-response-related pathways. This indicated that the differentially expressed miRNAs had a critical influence on T. gallinae infection. Novel_miR_741, which could inhibit the expression of PRKCQ, was down-regulated in the T group compared to the C group. It was proven that a decreased novel_miR_741 expression would increase the expression of PRKCQ and increase the immune response. This study brings new insights into understanding the mechanism of trichomonosis resistance. [ABSTRACT FROM AUTHOR]

(1) Background: Cytoplasmic male sterility (CMS) is important for exploiting heterosis. Soybean (Glycine max L.) has a low outcrossing rate that is detrimental for breeding sterile lines and producing hybrid seeds. Therefore, the molecular mechanism controlling the outcrossing rate should be elucidated to increase the outcrossing rate of soybean CMS lines; (2) Methods: The male–sterile soybean lines JLCMS313A (with a high outcrossing rate; HL) and JLCMS226A (with a low outcrossing rate; LL) were used for a combined analysis of the transcriptome (RNA–seq) and the targeted phenol metabolome; (3) Results: The comparison between HL and LL detected 5946 differentially expressed genes (DEGs) and 81 phenolic metabolites. The analysis of the DEGs and differentially abundant phenolic metabolites identified only one common KEGG pathway related to flavonoid biosynthesis. The qRT–PCR expression for eight DEGs was almost consistent with the transcriptome data. The comparison of the cloned coding sequence (CDS) regions of the SUS, FLS, UGT, and F3H genes between HL and LL revealed seven single nucleotide polymorphisms (SNPs) only in the F3H CDS. Moreover, five significant differentially abundant phenolic metabolites between HL and LL were associated with flavonoid metabolic pathways. Finally, on the basis of the SNPs in the F3H CDS, one derived cleaved amplified polymorphic sequence (dCAPS) marker was developed to distinguish between HL and LL soybean lines; (4) Conclusions: The flavonoid biosynthesis pathway may indirectly affect the outcrossing rate of CMS sterile lines in soybean. [ABSTRACT FROM AUTHOR]

Forest fires create burned and unburned areas on a spatial scale, with the boundary between these areas known as the fire boundary. Following an analysis of forest fire boundaries in the northern region of Yangyuan County, located in the Liangshan Yi Autonomous Prefecture of Sichuan Province, China, several key factors influencing the formation of fire boundaries were identified. These factors include the topography, vegetation, climate, and human activity. To explore the impact of these factors in different spaces on potential results, we varied the distances between matched sample points and built six fire environment models with different sampling distances. We constructed a matched case-control conditional light gradient boosting machine (MCC CLightGBM) to model these environment models and analyzed the factors influencing fire boundary formation and the spatial locations of the predicted boundaries. Our results show that the MCC CLightGBM model performs better when points on the selected boundaries are paired with points within the burned areas, specifically between 120 m and 480 m away from the boundaries. By using the MCC CLightGBM model to predict the probability of boundary formation under six environmental models at different distances, we found that fire boundaries are most likely to form near roads and populated areas. Boundary formation is also influenced by areas with significant topographic relief. It should be noted explicitly that this conclusion is only applicable to this study region and has not been validated for other different regions. Finally, the matched case-control conditional random forest (MCC CRF) model was constructed for comparison experiments. The MCC CLightGBM model demonstrates potential in predicting fire boundaries and fills a gap in research on fire boundary predictions in this area which can be useful in future forest fire management, allowing for a quick and intuitive assessment of where a fire has stopped. [ABSTRACT FROM AUTHOR]

Simple Summary: Semen cryopreservation remains the most applicable methodology for conserving and transmitting superior genetic backgrounds in poultry species. However, there is wide variability in the results of sperm viability and fertility due to susceptibility to cryodamage. The current study implemented a cryopreservation protocol based on rapid freezing of semen pellets supplemented with various levels of dimethylacetamide (DMA), focusing on in vitro quality, computer-assisted-sperm-analysis (CASA), and anti-freeze-associated gene expression of post-thawed rooster sperm. The current investigation provides novel results regarding the appropriate concentration and molecular mechanism by which DMA could be supplemented to frozen semen pellets and used as a successful protocol for sperm cryopreservation in poultry species. Sperm cryopreservation is an effective technique for conserving animal genetic diversity and transmitting superior genetic backgrounds, maintained via a non-invasive sampling and collection of huge quantities of sperm. Nevertheless, cryopreservation in avian species is not commercially viable because of the rooster sperm's susceptibility to damage. This study aims to estimate the impact of dimethylacetamide (DMA) as a cryoprotectant at different levels (3%, 6%, or 9%) on the post-thawed sperm quality, motility, antioxidant-biomarkers, and the expression of anti-freeze related genes. Semen samples were collected twice a week from twelve roosters aged 40 wk, weighing 3400 ± 70 g, and belonging to the Cairo-B2 chicken strain. Fresh semen samples were rapidly appraised, pooled, diluted with two volumes of a basic extender, and divided equally into three groups. The diluted groups were chilled at −20 °C for 7 min, then gently supplemented with 3, 6, or 9% pre-cooled DMA and equilibrated at 5 °C for a further 10 min. Semen pellets were formed by pipetting drops 7 cm above liquid nitrogen (LN2), which were then kept inside cryovials in the LN2. Thawing was performed 2 months later by taking 3–4 pellets of the frozen semen into a glass tube and warming it in a water bath for 8 s at 60 °C. The results showed that 3% DMA increased the proportion of total motile sperm, progressivity, viability, and plasma membrane integrity (%) compared to the 6% and 9% DMA groups. The lipid peroxidation and antioxidant enzyme activity were improved in the 3% group. At the same time, some anti-freeze-related genes' (including ras homolog family member A (RHOA), heat shock protein 70 (HSP70), and small nuclear ribonucleoprotein polypeptide A (SNRPA1)) expressions were upregulated within the 3% DMA group relative to other groups. In conclusion, the 3% DMA group maintained higher post-thawed sperm quality than the other tested groups. [ABSTRACT FROM AUTHOR]

Simple Summary: Vision is highly developed in fowl. Light not only provides ambient illumination, but also influences their physiological responses. Therefore, proper lighting management practices are crucial for improving the efficiency and welfare of commercial poultry operations. Light spectrum is the combination of different wavelengths of electromagnetic radiation produced by a lighting source. With a ban of traditional incandescent bulbs globally, the poultry industry is currently undergoing a shift to alternative lighting sources, such as light emitting diode (LED) bulbs, which permit the design of different and complex light spectrums output as required. The present study investigated the effects of three LED lights and one compact fluorescent lamp (CFL) with different spectrum characteristics on the performance during the pullet rearing and subsequent laying phase of Beijing-You chickens, a typical indigenous chicken breed in China. Results showed that the four lights did not show differences in feed efficiency before 17 week of age; the LED light with more balanced light spectrums (27% green light, 30% blue light, 22% yellow light, and 21% red light) promotes the prepubertal growth; and the LED light of more blue and green light (35% green light, 35% blue light, 18% yellow light, and 12% red light) provides proper sexual maturation age and better egg-laying persistence. These results inspire better design of LED lights for the indigenous chicken industry. Light presents an important exogenous factor for poultry. This study examined effects of LED lights with different defined spectrums on growth and reproduction of indigenous Beijing-You chickens. A total of 576 one-day old female chicks were divided into 16 rooms, and each were exposed to four different lights: LED A (21% green light, 30% blue light, 24% yellow light, and 25% red light), B (35%, 35%, 18%, and 12%), C (27%, 30%, 22%, and 21%), or compact fluorescent lamps (CFL, 15%, 28%, 41%, and 16%). Results showed that feed intake and feed conversion ratio were comparable among treatments throughout the 17 week rearing period (p > 0.05). LED C showed similar body weight gain with CFL, but higher than LED A and B. The CFL birds start to lay on 132.25 d, while LED B did not lay until 148.25 d. The age at 50% egg production did not vary among groups (p = 0.12). Total egg number until 43 week of LED B was higher than others (p < 0.05). Therefore, LED lights with defined spectral proportion have different effects on chickens' growth and reproduction. The LED C promotes the prepubertal growth, and the LED B provides proper sexual maturation age and better egg-laying persistence. [ABSTRACT FROM AUTHOR]

Ex situ preservation is an important method in the preservation of chickens, and cryopreservation of semen is the only method for gamete preservation at present. During the last two decades, many studies have been performed to develop standard chicken semen cryopreservation technology and achieve great progress. Many attempts and methods were investigated to adapt subspecies or different breeds. In this paper, we firstly reviewed the main factors affecting cryopreservation of chicken sperm, including the unique structure and characteristics of the spermatozoa. Secondly, the studies on key points of the chicken sperm cryopreservation technology, including semen dilution, cryoprotectants, equilibration time, packaging types, and freezing and thawing rates were summarized to generate the optimal parameters. Then, the mechanism underlying freezing damage and freezability revealed by recent omics methods relevant to the efficiency of cryopreservation were discussed. This review will provide relevant reference for the future investigation of poultry semen cryopreservation technology. [ABSTRACT FROM AUTHOR]

This study compared floor (FS) with cage systems (CS) for slow-growing meat-type chickens in terms of muscle fiber characteristics, carcass characteristics, and meat quality. Following the design of a factorial arrangement of 2 housing systems × 2 genders, 180 male and 180 female Beijing You chickens of 8 weeks old were allocated to FS and CS. At the end of 17 weeks, five males and five females from each replicate were selected for measurement. No difference was observed in body, carcass, or eviscerated weight (p > 0.05). FS birds showed higher muscle yield and lower abdominal fat composition (p < 0.05). Inosine-5′-monophosphate (IMP) content was not affected by housing system or gender (p > 0.05). On the contrary, intramuscular fat (IMF) content was affected by both in a way that CS birds and females had higher IMF content (p < 0.05). FS birds had a higher percentage of white muscle fibers (p < 0.05). In conclusion, carcass characteristics, meat quality, and muscle fiber type of slowing-growing broilers are influenced: rearing on the floor may improve muscle development and reduce fat deposition without impairing marketing weight and rearing in cages may improve IMF content. [ABSTRACT FROM AUTHOR]

Crossbreeding is normally applied to improve the economical traits of chickens. However, feed efficiency and its relationship with egg quality have rarely been explored in crossbreds. Herein, White Leghorn and Beijing You chickens were selected to generate purebreds (WW, YY) and reciprocal crossbreds (YW, WY), which were evaluated in terms of daily feed intake (DFI), feed conversion ratio (FCR), and residual feed intake (RFI) at 43 to 46 and 69 to 72 weeks of age, respectively. We found that WY was more efficient than YW in both laying periods. The correlation analysis showed that RFI was highly correlated with DFI (0.49 to 0.84) but unrelated to egg mass, and FCR was negatively correlated with egg mass (−0.77 to −0.43) in both purebreds and crossbreds. Moreover, RFI was not correlated with egg quality traits within each genetic group, except for the egg yolk ratio (0.27) in WW. FCR was negatively correlated with eggshell weight and thickness (−0.33 to −0.19) in WW and WY. Compared to FCR, selection for RFI could improve feed efficiency without significant changes in egg mass and quality in chickens. These findings provide new insights into the improvement of feed efficiency using rational parental lines in chicken crossbreeding. [ABSTRACT FROM AUTHOR]

Simple Summary: Although sperm cryopreservation has a great potential for application in the poultry industry, it is still very limited at the economical scale due to the low fertility of frozen/thawed avian spermatozoa. Dimethylacetamide (DMA) has been widely employed as a cryoprotectant for the cryopreservation of chicken spermatozoa, but with variable results in motility and fertility. To determine the appropriate concentration of DMA in the chicken semen freezing extender, in vitro sperm quality and motility analyses and in vivo field trials based on the fertility of the frozen/thawed rooster sperm were conducted in the present study. The antioxidant biomarkers and novel anti-freeze-associated genes were also analyzed in the post-thawed sperm. Results conclude that DMA is preferably used at a low concentration to obtain applicable results in sperm motility and fertility after thawing without harming the quality and antioxidant system defense. The current study could highlight the possible molecular mechanisms behind the obtained fertility results of DMA-frozen sperm, especially when artificial insemination is implemented in the poultry industry. Sperm cryopreservation is of great importance for the poultry industry but still needs to be optimized. The high susceptibility of poultry sperm to cryodamage leads to low fertility rates after cryopreservation. Therefore, the present study aimed at evaluating the effect of including a cryoprotectant, dimethylacetamide (DMA), in the chicken semen freezing extenders at a final concentration of 3%, 6%, or 9% on the post-thawed sperm motility, quality, antioxidant biomarkers, anti-freeze gene expression, and fertilizing ability. Results showed that the total motile sperm, progressivity, and viability were quadratically increased (p < 0.05) in the 6% DMA group. The antioxidant enzyme activity and lipid peroxidation were negatively (p < 0.05) affected by the increase in DMA concentration. Furthermore, some anti-freeze-associated genes such as heat shock protein 70 (HSP70) and ras homolog family member A (RHOA) were linearly and quadratically down-regulated (p < 0.05) with the high concentration of DMA. Finally, the fertility and hatchability rates did not indicate statistical differences between DMA groups. It can be concluded that using the low concentration of 3–6% DMA in the freezing semen extender is preferable to obtain acceptable results in the post-thawed sperm quality and fertility. [ABSTRACT FROM AUTHOR]

A forest fire susceptibility map generated with the fire susceptibility model is the basis of fire prevention resource allocation. A more reliable susceptibility map helps improve the effectiveness of resource allocation. Thus, further improving the prediction accuracy is always the goal of fire susceptibility modeling. This paper developed a forest fire susceptibility model based on an ensemble learning method, namely light gradient boosting machine (LightGBM), to produce an accurate fire susceptibility map. In the modeling, a subtropical national forest park in the Jiangsu province of China was used as the case study area. We collected and selected eight variables from the fire occurrence driving factors for modeling based on correlation analysis. These variables are from topographic factors, climatic factors, human activity factors, and vegetation factors. For comparative analysis, another two popular modeling methods, namely logistic regression (LR) and random forest (RF) were also applied to construct the fire susceptibility models. The results show that temperature was the main driving factor of fire in the area. In the produced fire susceptibility map, the extremely high and high susceptibility areas that were classified by LR, RF, and LightGBM were 5.82%, 18.61%, and 19%, respectively. The F1-score of the LightGBM model is higher than the LR and RF models. The accuracy of the model of LightGBM, RF, and LR is 88.8%, 84.8%, and 82.6%, respectively. The area under the curve (AUC) of them is 0.935, 0.918, and 0.868, respectively. The introduced ensemble learning method shows better ability on performance evaluation metrics. [ABSTRACT FROM AUTHOR]

The silkworm's Cat L-like gene, which encodes a lysosomal cathepsin L-like cysteine protease, is thought to be part of the insect's innate immunity via an as-yet-undetermined mechanism. Assuming that the primary function of Cat L-like is microbial degradation in mature phagosomes, we hypothesise that the suppression of the Cat L-like gene expression would increase Bacillus thuringiensis (Bt) bacteraemia and toxicity in knockdown insects. Here, we performed a functional analysis of Cat L-like in larvae that were fed mulberry leaves contaminated with a commercial biopesticide formulation based on Bt kurstaki (Btk) (i.e., Dipel) to investigate its role in insect defence against a known entomopathogen. Exposure to sublethal doses of Dipel resulted in overexpression of the Cat L-like gene in insect haemolymph 24 and 48 h after exposure. RNA interference (RNAi)-mediated suppression of Cat L-like expression significantly increased the toxicity of Dipel to exposed larvae. Moreover, Btk replication was higher in RNAi insects, suggesting that Cat L-like cathepsin may be involved in a bacterial killing mechanism of haemocytes. Finally, our results confirm that Cat L-like protease is part of the antimicrobial defence of insects and suggest that it could be used as a target to increase the insecticidal efficacy of Bt-based biopesticides. [ABSTRACT FROM AUTHOR]

The cytoplasmic male sterility/restorer-of-fertility (CMS/Rf) system plays a vital role in high-efficiency hybrid seed production in crops, including soybean (Glycine max (L.) Merr.). The markers linked to fertility restoration and the restorer-of-fertility (Rf) genes are essential because they can facilitate the breeding of new CMS lines and production of commercial hybrid soybean seeds. To date, several soybean Rf genes have been mapped to various genetic loci in diverse genetic populations. However, the mapping range of restorer genes remains narrow, with relatively limited practical applicability. Therefore, in the present study, F2 and F3 segregating populations derived from the CMS line JLCMS5A crossed with the restorer line JLR2 were developed and used for Rf3 gene fine mapping. Genetic investigation indicated that the restorer line JLR2 was controlled by a single dominant gene, Rf3. By integrating bulk-segregant analysis and next-generation sequencing, a 4 Mb region on chromosome 9 was identified, which was most likely the target region harboring the candidate gene responsible for fertility restoration. This region was further narrowed down to 86.44 Kb via fine mapping in F2 and F3 populations using SSR, InDel, and dCAPS markers. This region contained 10 putative genes (Glyma.09G171100–Glyma.09G172000). Finally, Glyma.09G171200, which encodes a mitochondria-targeted pentatricopeptide repeat protein, was proposed as the potential candidate for Rf3 using sequence alignment and expression analysis in restorer and CMS lines. Based on single-nucleotide polymorphisms in Glyma.09G171200, a CAPS marker co-segregated with Rf3 named CAPS1712 was developed. Our results will be fundamental in the assisted selection and creation of potent lines for the production and rapid selection of novel restorer lines. [ABSTRACT FROM AUTHOR]

Pigeon belongs to altrices. Squab cannot forage independently. Nutrition can only be obtained from crop milk secreted by male and female pigeon. miRNA could regulate many biological events. However, the roles of miRNA and ceRNA in regulating crop milk production are still unknown. In this study, we investigated the miRNAs expression profile of female pigeon crop, explored the potential key genes, and found the regulatory mechanisms of crop milk production. A total of 71 miRNAs were identified differentially expressed significantly. Meanwhile, miR-20b-5p, miR-146b-5p, miR-21-5p, and miR-26b-5p were found to be the key miRNAs regulating lactation. Target genes of these miRNAs participated mainly in cell development; protein and lipid synthesis; and ion signaling processes, such as cell-cell adhesion, epithelial cell morphogenesis, calcium signaling pathway, protein digestion, and absorption. In the ceRNA network, miR-193-5p was located in the central position, and miR-193-5p/CREBRF/LOC110355588, miR-460b-5p/GRHL2/MSTRG.132954, and miR-193-5p/PIK3CD/LOC110355588 regulatory axes were believed to affect lactation. Collectively, our findings enriched the miRNA expression profile of pigeon and provided novel insights into the microRNA-associated-ceRNA networks regulating crop milk production in pigeon. [ABSTRACT FROM AUTHOR]

The use of herbicides is an effective and economic way to control weeds, but their availability for rapeseed is limited due to the shortage of herbicide-resistant cultivars in China. The single-point mutation in the acetohydroxyacidsynthase (AHAS) gene can lead to AHAS-inhibiting herbicide resistance. In this study, the inheritance and molecular characterization of the tribenuron-methyl (TBM)-resistant rapeseed (Brassica napus L.) mutant, K5, are performed. Results indicated that TBM-resistance of K5 was controlled by one dominant allele at a single nuclear gene locus. The novel substitution of cytosine with thymine at position 544 in BnAHAS1 was identified in K5, leading to the alteration of proline with serine at position 182 in BnAHAS1. The TBM-resistance of K5 was approximately 100 times that of its wild-type ZS9, and K5 also showed cross-resistance to bensufuron-methyl and monosulfuron-ester sodium. The BnAHAS1544T transgenic Arabidopsis exhibited higher TBM-resistance than that of its wild-type, which confirmed that BnAHAS1544T was responsible for the herbicide resistance of K5. Simultaneously, an allele-specific marker was developed to quickly distinguish the heterozygous and homozygous mutated alleles BnAHAS1544T. In addition, a method for the fast screening of TBM-resistant plants at the cotyledon stage was developed. Our research identified and molecularly characterized one novel mutative AHAS allele in B. napus and laid a foundation for developing herbicide-resistant rapeseed cultivars. [ABSTRACT FROM AUTHOR]

Pigeons have the ability to produce milk and feed their squabs. The genetic mechanisms underlying milk production in the crops of 'lactating' pigeons are not fully understood. In this study, RNA sequencing was employed to profile the transcriptome of lncRNA and mRNA in lactating and non-'lactating' pigeon crops. We identified 7066 known and 17,085 novel lncRNAs. Of these lncRNAs, 6166 were differentially expressed. Among the 15,138 mRNAs detected, 6483 were differentially expressed, including many predominant genes with known functions in the milk production of mammals. A GO annotation analysis revealed that these genes were significantly enriched in 55, 65, and 30 pathways of biological processes, cellular components, and molecular functions, respectively. A KEGG pathway enrichment analysis revealed that 12 pathways (involving 544 genes), including the biosynthesis of amino acids, the propanoate metabolism, the carbon metabolism and the cell cycle, were significantly enriched. The results provide fundamental evidence for the better understanding of lncRNAs' and differentially expressed genes' (DEGs) regulatory role in the molecular pathways governing milk production in pigeon crops. To our knowledge, this is the first genome-wide investigation of the lncRNAs in pigeon crop associated with milk production. This study provided valuable resources for differentially expressed lncRNAs and mRNAs, improving our understanding of the molecular mechanism of pigeon milk production. [ABSTRACT FROM AUTHOR]

Pigeon belongs to altrices. Squab cannot forage independently. Nutrition can only be obtained from crop milk secreted by male and female pigeon. miRNA could regulate many biological events. However, the roles of miRNA and ceRNA in regulating crop milk production are still unknown. In this study, we investigated the miRNAs expression profile of female pigeon crop, explored the potential key genes, and found the regulatory mechanisms of crop milk production. A total of 71 miRNAs were identified differentially expressed significantly. Meanwhile, miR-20b-5p, miR-146b-5p, miR-21-5p, and miR-26b-5p were found to be the key miRNAs regulating lactation. Target genes of these miRNAs participated mainly in cell development; protein and lipid synthesis; and ion signaling processes, such as cell-cell adhesion, epithelial cell morphogenesis, calcium signaling pathway, protein digestion, and absorption. In the ceRNA network, miR-193-5p was located in the central position, and miR-193-5p/ CREBRF /LOC110355588, miR-460b-5p/ GRHL2 /MSTRG.132954, and miR-193-5p/ PIK3CD /LOC110355588 regulatory axes were believed to affect lactation. Collectively, our findings enriched the miRNA expression profile of pigeon and provided novel insights into the microRNA-associated-ceRNA networks regulating crop milk production in pigeon.