Comparative iTRAQ proteomics revealed proteins associated with horn development in yak

Abstract

BackgroundThe practice of dehorning yak raises animal safety concerns, which have been addressed by selective breeding to obtain genetically hornless yak. The POLLED locus in yak has been studied extensively; however, little is known regarding the proteins that regulate horn bud development.MethodsA differential proteomic analysis was performed to compare the skin from the horn bud region of polled yak fetuses and the horn bud tissue of horned yak fetuses using isobaric tags for relative and absolute quantitation (iTRAQ) technology coupled with 2D LC-MS/MS.ResultsOne hundred differentially abundant proteins (DAPs) were identified. Of these, 29 were up-regulated and 71 were down-regulated in skin from the horn bud region of polled fetuses when compared to the horn bud tissue of horned fetuses. Bioinformatics analyses showed that the up-regulated DAPs were mainly associated with metabolic activities, while the down-regulated DAPs were significantly enriched in cell adhesion and cell movement activities.ConclusionsWe concluded that some important proteins were associated with cell adhesion, cell motility, keratinocyte differentiation, cytoskeleton organization, osteoblast differentiation, and fatty acid metabolism during horn bud development. These results advance our understanding of the molecular mechanisms underlying horn development.Electronic supplementary materialThe online version of this article (10.1186/s12953-018-0141-9) contains supplementary material, which is available to authorized users.

Understanding the effects of the bovine POLLED variants

“…Lastly, the horn bud has thick nerve bundles whereas nerve bundles are absent in frontal skin (Capitan et al ; Allais‐Bonnet et al ; Wiener et al ). Similar observations have been made for yak fetuses (Li et al ). There is no evidence of ossification in the fetal horn bud (Wiener et al ), and horn growth and ossification occur approximately 1 month after birth (Dove ).…”

“…Polled fetuses carrying the Celtic variant do not develop horn buds, forming only smooth tissue that is histologically indistinguishable from frontal skin tissue (Allais‐Bonnet et al ; Wiener et al ). Horn bud development is also absent in yak fetuses carrying the Mongolian variant (Li et al ), but has not been investigated in fetuses homozygous for the Friesian and Guarani variants.…”

“…Gene expression studies of horn bud tissue from horned and polled cattle can be used to identify genetic pathways involved in normal horn development and provide clues about the mechanism by which POLLED variants prevent horns. Several studies have investigated gene expression and protein abundance in bovine fetal and neonatal horn bud tissue (Allais‐Bonnet et al ; Wiedemar et al ; Li et al ).…”

“…A proteomic study of three polled (P M ) and three‐horned yak fetuses at 80–90 days development investigated differentially abundant proteins (DAPs) in tissue from the horn bud region (Li et al ). This study identified 29 upregulated proteins and 71 downregulated proteins in the polled fetus compared with horned fetuses.…”

Phenotypic Analysis Combined with Tandem Mass Tags (TMT) Labeling Reveal the Heterogeneity of Strawberry Stolon Buds

“…Comparative proteomics is a useful approach for identifying functional proteins in illustrating the developmental regulation mechanism of plants [27][28][29][30]. Recently, with the tremendous acquisition of the plant reference genome data, more and more comparative proteomics approaches have been applied for studying bud heterogeneity in crops [17][18][19][20].…”