Location: Genetics and Animal Breeding
Title: Distinctive gene expression patterns and imprinting signatures revealed in reciprocal crosses between cattle sub-speciesAuthor
LIU, RUIJIE - University Of Adelaide | |
TEARLE, RICK - University Of Adelaide | |
LOW, WAI YEE - University Of Adelaide | |
CHEN, TONG - University Of Adelaide | |
THOMSEN, DANA - University Of Adelaide | |
Smith, Timothy - Tim | |
HIENDLEDER, STEFAN - University Of Adelaide | |
WILLIAMS, JOHN - Università Cattolica Del Sacro Cuore |
Submitted to: BMC Genomics
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/21/2021 Publication Date: 6/3/2021 Citation: Liu, R., Tearle, R., Low, W., Chen, T., Thomsen, D., Smith, T.P.L., Hiendleder, S., Williams, J.L. 2021. Distinctive gene expression patterns and imprinting signatures revealed in reciprocal crosses between cattle sub-species. Biomed Central (BMC) Genomics. 22. Article 410. https://doi.org/10.1186/s12864-021-07667-2. DOI: https://doi.org/10.1186/s12864-021-07667-2 Interpretive Summary: There are two subspecies of cattle in the world today, called taurine and indicine cattle types. The taurine types are typified by common breeds in the U.S. like Angus, Holstein, or Hereford and have been intensively selected for production traits of superior milk or meat quality. The indicine types are typified in the U.S. by the Brahman breed, and are known for their tropical adaptations and superior pest and disease resistance qualities, but generally lag in the production traits selected in taurine cattle. Numerous efforts to combine the positive attributes of both types by crossbreeding have been conducted, resulting in some new breeds such as Brangus or Beefmaster. Studies have shown variable effects of crossbreeding depending upon the sex of the animal of each breed used (that is, the results can be different if Angus sires are used on Brahman cows, compared with using Brahman sires on Angus cows). The present work is an effort to understand the differences between the taurine and indicine types using gene expression profiling in Angus and Brahman cattle breeds, and includes crossbreeds of the two types that supports analysis of effects that are sex and breed-specific. The study identified numerous genes that are expressed at different levels in the two breeds, and the crossbred animals were key to identifying the true breed-specific differences and discovering genes that may drive the breed differences observed and provide new insights into contrasting effects that emerge when using a particular sex of each type in crossbreeding. Technical Abstract: Background: There are two genetically distinct subspecies of cattle, Bos taurus taurus and Bos taurus indicus, which arose from independent domestication events. The two types of cattle show substantial phenotypic differences, some of which emerge during fetal development and are reflected in birth outcomes, including birth weight. We explored gene expression profiles in the placenta and four fetal tissues at mid-gestation from one taurine (Bos taurus taurus; Angus) and one indicine (Bos taurus indicus; Brahman) breed and their reciprocal crosses. Results: In total 120 samples were analysed from a pure taurine breed, an indicine breed and their reciprocal cross fetuses, which identified 6456 differentially expressed genes (DEGs) between the two pure breeds in at least one fetal tissue of which 110 genes were differentially expressed in all five tissues examined. DEGs shared across tissues were enriched for pathways related to immune and stress response functions. Only the liver had a substantial number of DEGs when reciprocal crossed were compared among which 310 DEGs were found to be in common with DEGs identified between purebred livers; these DEGs were significantly enriched for metabolic process GO terms. Analysis of DEGs across purebred and crossbred tissues suggested an additive expression pattern for most genes, where both paternal and maternal alleles contributed to variation in gene expression levels. However, expression of 5% of DEGs in each tissue was consistent with parent of origin effects, with both paternal and maternal dominance effects identified. Conclusions: These data identify candidate genes potentially driving the tissue-specific differences between these taurine and indicine breeds and provide a biological insight into parental genome effects underlying phenotypic differences in bovine fetal development. |