Search

Simple Summary: Compared with traditional breeding methods, molecular marker breeding can greatly speed up the process of livestock breeding to improve the production performance of economic traits. As one form of genetic variation, copy number variations could be used for molecular marker breeding. This study explored CNVs in bovine CLCN2 genes on account of this gene possibly being involved in cell volume regulation, transepithelial transport and cell proliferation. We investigated their association with growth traits in four Chinese cattle breeds. Our results provide evidence that there are two different copy number variations in CLCN2, which are associated with growth traits in two different Chinese cattle populations and could be used as candidate markers for cattle molecular breeding. Copy number variation (CNV) can affect gene function and even individual phenotypic traits by changing the transcription and translation level of related genes, and it also plays an important role in species evolution. Chloride voltage-gated channel 2 (CLCN2) encodes a voltage-gated chloride channel (CLC-2), which has a wide organ distribution and is ubiquitously expressed. Based on previous studies, we hypothesize that CLCN2 could be a candidate gene involved in cell volume regulation, transepithelial transport and cell proliferation. This study aimed to explore CNVs in the CLCN2 gene and investigate its association with growth traits in four Chinese cattle breeds (Yunling cattle, Xianan cattle, Qinchuan cattle and Pinan cattle). We identified there are two copy number variation regions (CNV1: 3600 bp, including exon 2–11; CNV2: 4800 bp, including exon 21–22) of the CLCN2 gene. The statistical analysis showed that the CNV1 mutation in the YL cattle population was significantly associated with cannon circumference (p < 0.01). The CNV2 mutation in the XN cattle population had a significant effect on body slanting length, chest girth and body weight (p < 0.05). In the YL cattle, the association analysis of CLCN2 gene CNV1 and CNV2 combination with cannon circumference was significant (p < 0.01). Our results provide evidence that CNV1 and CNV2 in CLCN2 are associated with growth traits in two different cattle populations and could be used as candidate markers for cattle molecular breeding. [ABSTRACT FROM AUTHOR]

Abstract\nSIMPLE SUMMARYCattle are sensitive to temperature fluctuations but adapt well to inclement weather conditions. When environmental temperatures exceed specific thresholds, heat stress becomes a critical concern for cattle. The TRPM2 gene, which resides on cattle chromosome 1 encodes a TRP channel protein, holding a unique capacity to sense temperature changes and facilitate rapid response to avoid heat stress. Here, we utilized the Bovine Genome Variation Database (BGVD) (http://animal.omics.pro/code/index.php/BosVar), and identified a missense mutation site, c.805A > G: p. Met269Val (rs527146862), within the TRPM2 gene. To elucidate the functional assessment of this mutation in temperature adaptation attributes of Chinese cattle, we genotyped 407 samples from 20 distinct breeds representing diverse climatic zones across China. The association analysis incorporates three temperature parameters and revealed compelling insights in terms of allele frequency. Interestingly, the prevalence of the wild-type allele A was notably higher among northern cattle breeds and this trend diminished gradually as observed in southern cattle populations. Conversely, the mutant-type allele G demonstrated a contrasting trend. Moreover, southern cattle exhibited markedly higher frequencies of GG and GA genotypes (P < 0.01). The presence of heterozygous and homozygous mutations appears to confer an enhanced capacity for adaptation to elevated temperatures. These results provide unequivocal correlation evidence between TRPM2 genotypes (AA, GA, GG) and environmental temperature parameters and comprehend the genetic mechanisms governing temperature adaptation in cattle. This provides valuable insights for strategic breed selection across diverse climatic regions, thereby aiding livestock production amid evolving climate challenges.The TRPM2 gene encodes TRP channel protein that helps animals in combating heat stress. Twenty Chinese local cattle breeds were genotyped, and association analysis was performed. This investigation encompasses the distribution pattern of the missense mutation locus rs527146862 of the TRPM2 gene in southern, northern, and central cattle populations. The results demonstrated a significant relationship between rs527146862 locus and temperature adaptation attributes in Chinese cattle. [ABSTRACT FROM AUTHOR]

Circular RNA (circRNA) is endogenous noncoding RNA found throughout the eukaryotic genome. It regulates several biological activities at the transcription or post-transcription level. However, the underlying function of circRNA in bovine skeletal muscle development remains unknown. Here, we identified a novel circRNA, circNDST1 , and investigated its function and mechanism on the proliferation and differentiation of bovine myoblasts. At the molecular and cellular levels, circNDST1 could promote bovine myoblasts proliferation and inhibit differentiation. Mechanistically, circNDST1 is expressed in the cytoplasmic of myoblast and was enriched by protein Ago2. circNDST1 acts as a competing endogenous RNA that sponges miR-411a and alleviates the inhibitory effect on its target gene, Smad4 . miR-411a and Smad4 were also involved in regulating bovine myoblast proliferation and differentiation. These findings suggest that circNDST1 functions as a competing endogenous RNA and regulates bovine myoblast proliferation and differentiation through the miR-411a/ Smad4 axis.

Brahman cattle are tolerant to parasite challenges and heat stress. Yunling cattle are three-way hybrids that are half Brahman cattle, a fourth Murray Grey cattle and a fourth Yunnan Yellow cattle, with good beef performance. The hematological and biochemical parameters can reflect the physiology and metabolic conditions of cattle, and there are valuable indicators of production performance and adaptability that can be found by studying the cattle. To assess the health status and differences, we compared 55 hematological and biochemical parameters of 28 Brahman cattle and 65 Yunling cattle using an automatic biochemical analyzer. Our results showed that 27 hematological and biochemical indices of Brahman cattle were lower than those of Yunling cattle, whereas the other parameters were higher. There are 20 indices with significant differences that were detected between Brahman and Yunling cattle (with p ≤ 0.01 or 0.01 ≤ p ≤ 0.05, respectively), and no significant differences were found for other indices (p > 0.05). Based on these results, Yunling cattle may have a better physical condition than Brahman cattle, may be better at adapting to local environments, and can maintain a good production and reproduction performance. As a new breed that is half Brahman, the abilities of Yunling cattle, including adaptability, stress resistance and tolerance to crude feed, were better than Brahman cattle under the same management conditions.

Considerable evidence has demonstrated that the μ -calpain ( CAPN1 ) gene and its inhibitor calpastatin ( CAST ) gene are major factors affecting meat quality. Marker-assisted selection (MAS) has been widely used to improve beef quality traits. Therefore, the objective of the present study was to investigate the single nucleotide polymorphisms (SNPs) of bovine CAPN1 and CAST genes using 367 animals representing the four main Chinese cattle breeds and to explore the effects of these SNPs on meat quality traits. Two SNPs within CAPN1 and one SNP in CAST were successfully identified in cattle. Genetic diversity analyses suggested that most SNPs in the four breeds exhibited a moderate genetic diversity. Moreover, associations between individual markers and meat quality traits were analyzed in Chinese Simmental cattle. The CAPN1 4558 A > G locus was found to be significantly associated with shear force value (SFV) and marbling score (BMS), and CAPN1 4684 C > T exerted a significant effect on SFV, while the CAST genotype was not significantly associated with any of the measured traits. SFV, commonly used to measure meat tenderness, represents an important quality trait as it contributes to the flavor of cooked meat. This work confirms the effect of CAPN1 on beef tenderness and lays an important foundation for future cattle breeding., Competing Interests: The authors declare that they have no conflict of interest., (Copyright: © 2018 Xiaomei Sun et al.)