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There are many limitations when using traditional laboratory species. Limits on variation, may result in limited outcomes, at both the species and individual level, due to different individuals/species having diverse physiological processes, or differing molecular and genetic mechanisms. By using a variety of model species, we will be able to develop creative solutions to biological problems and identify differences of which we were not previously aware. The laboratory mouse has been a suitable model species for various mammalian studies, however most are bred specifically for laboratory research with limited variability due to selective breeding. Marsupial models offer unique research opportunities compared to eutherian models. We believe that there should be an expansion in marsupial model species, and the introduction of the red‐tailed phascogale (Phascogale calura), a dasyurid marsupial, should be one of them. Phascogales are easily managed in captivity, and there are now multiple studies involving their development, reproduction, nutrition, behavior and immune system, which can serve as a baseline for future studies. The addition of the phascogale as a model species will improve future mammalian studies by introducing variability and offer alternate solutions to biological problems, particularly in the areas of genetics, nutrition, immunology, the neuro‐endocrine system, and ageing, due to their semelparous reproductive strategy and hence, subsequent predictive physiology. In this review, we provide information based on existing research on red‐tailed phascogales to support their inclusion as a model species. Highlights: Traditional laboratory species are limited in variation, hence can limit scientific outcomes.Red‐tailed phascogales are semelparous and easily managed in captivity.They offer an alternative animal model to investigate biological problems. [ABSTRACT FROM AUTHOR]

Marsupials and eutherians are mammals that differ in their physiological traits, predominately their reproductive and developmental strategies; eutherians give birth to well-developed young, while marsupials are born highly altricial after a much shorter gestation. These developmental traits also result in differences in the development of the immune system of eutherian and marsupial species. In eutherians, B-cells are the key to humoral immunity as they are found in multiple lymphoid organs and have the unique ability to mediate the production of antigen-specific antibodies in the presence of extracellular pathogens. The development of B-cells in marsupials has been reported and hypothesised to be similar to that of eutherians, except that haematopoiesis occurs in the liver, postpartum, until the bone marrow fully matures. In eutherians, specific genes are linked to specific stages in B-cell development, maturation, and differentiation processes, and have been identified including immunoglobulins (heavy and light chains), cluster of differentiation markers (CD10, 19, 34 and CD79α/β), signal transduction molecules (BTK, Lyn and Syk) and transcriptional regulators (EBF1, E2A, and Pax5). This review aims to discuss the known similarities and differences between marsupial and eutherian B-cells, in regards to their genetic presence, homology, and developmental stages, as well as to highlight the areas requiring further investigation. By enhancing our understanding of the genes that are involved with B-cells in the marsupial lineage, it will, in turn, aid our understanding of the marsupial immune system and support the development of specific immunological reagents for research and wildlife conservation purposes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

An ability to characterize the age of mosquito populations could provide cost-effective and compelling entomological evidence for the potential epidemiological impacts of vector control. The average age of a mosquito population is the most important determinant of vectorial capacity and the likelihood of disease transmission. Yet, despite decades of research, defining the age of a wild-caught mosquito remains a challenging, impractical, and unreliable process. Emerging chemometric and existing transcriptional approaches may overcome many of the limitations of current morphological techniques, but their utility in terms of field-based monitoring programmes remains largely untested. Herein, we review the potential advantages and disadvantages of new and existing age-grading tools in an operational context., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Antimicrobial substances in serum include circulating complement proteins and acute phase proteins (APPs). We identified gene sequences for APPs, haptoglobin (Hp), C-reactive protein (CRP) and serum amyloid A (SAA) in marsupial genomes. Hp and SAA levels were measured in red-tailed phascogale (Phascogale calura) sera using commercially available assays. Hp levels were higher in males than females, while SAA levels suggest the phascogales used in this study were healthy. Serum was co-cultured with four bacterial species. Bacterial growth was inhibited after incubation at 37°C, however effectiveness differed with bacteria and incubation time. The least amount of bacterial growth was noticed after introduction to K. pneumoniae, and most when introduced to P. aeruginosa. Despite marsupials not having mature immune tissues at birth, and unable to mount specific immune responses, this study suggests other immune strategies, such as APPs in serum likely aid marsupials in their defence against pathogens., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Marsupials are born immunologically premature, relying on cells and molecules in maternal milk for immune protection. Both immunoglobulin and complement proteins have been identified in marsupial milk, but the expression of specific complement proteins remains largely unexplored. We report partial cDNA sequences for two complement-activating proteins, C3, C1r, CFP and MASP2, in liver tissues from red-tailed phascogale (Phascogale calura). Conservation of functionally relevant motifs were identified in the translated cDNA sequences from phascogale C3, CFP and MASP2 and their eutherian homologues. Gene expression of representative molecules from each of the major complement pathways was also investigated in whole body tissues from 1 to 18 day old animals and liver tissues from 31-day to 14-month old animals. Average complement expression in whole bodies and liver tissues of C1r, CFP, MASP2 and C3 increased significantly in juveniles compared to pouch young, presumably due to the maturation of the young's own complement system. Comparing expression in liver tissues only, we found that the average CFP expression were higher in pouch young compared to juveniles, while results were still statistically similar to the average expression of all tissues for C1r, MASP2 and C3. The average complement expression then significantly decreased as the animals aged into adulthood., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Reference genes serve an important role as an endogenous control/standard for data normalisation in gene expression studies. Although reference genes have recently been suggested for marsupials, independent analysis of reference genes on different immune tissues is yet to be tested. Therefore, an assessment of reference genes is needed for the selection of stable, expressed genes across different marsupial tissues., Methods: The study was conducted on red-tailed phascogales ( Phascogale calura ) using five juvenile and five adult males. The stability of five reference genes (glyceraldehyde-3-phosphate dehydrogenase, GAPDH ; β -actin, ACTB ; 18S rRNA, 18S; 28S rRNA , 28S; and ribosomal protein L13A, RPL13A ) was investigated using SYBR Green and analysed with the geNorm application available in qBase PLUS software., Results: Gene stability for juvenile and adult tissue samples combined show that GAPDH was most stable in liver and lung tissue, and 18S in small intestine and spleen. While all reference genes were suitable for small intestine and spleen tissues, all reference genes except 28S were stable for lung and only 18S and 28S were stable for liver tissue. Separating the two age groups, we found that two different reference genes were considered stable in juveniles ( ACTB and GAPDH ) and adults ( 18S and 28S ), and RPL13A was not stable for juvenile small intestine tissue. Except for 28S , all reference genes were stable in juvenile and adult lungs, and all five reference genes were stable in spleen tissue., Discussion: Based on expression stability, ACTB and GAPDH are suitable for all tissues when studying the expression of marsupials in two age groups, except for adult liver tissues. The expression stability between juvenile and adult liver tissue was most unstable, as the stable reference genes for juveniles and adults were different. Juvenile and adult lung, small intestine and spleen share similar stable reference genes, except for small intestine tissues where all reference genes were stable in adults but RPL13A was not suitable in juveniles., Competing Interests: The authors declare there are no competing interests.