Xi'an, June 21 (China News Service) -- Why do cows, sheep and deer have horns? The academic journal "Science" magazine published a research paper online on the 21st, from a genetic point of view, it was proposed for the first time that the horns of ruminants have the same cell origin - head neurovertebral stem cells, and their development process uses the basic same gene regulatory pathways, providing evidence for the ruminant horns to have a single evolutionary origin and development mechanism.
Jiang Yu and the graduate students are at work. Photo by Jin Jun
Northwest A&F University revealed on the 21st that the paper "Genetic Basis of Ruminant Horn Occurrence and Development and Rapid Regeneration of Deer Antler Velvet" was completed by the research team of Professor Jiang Yu of the College of Animal Science and Technology of the university and 9 domestic and foreign units such as Northwestern Polytechnical University.
The study found that cattle, sheep and deer have horns, and what are the similarities and differences between the horns of cattle and sheep and the horns of deer from genetic development? In fact, they all belong to the suborder Horned order of ruminants, and are the only surviving mammals with bony appendages on their skulls, and this appendage is horns.
Different animal groups of the subhorned order have their own unique forms of horns, such as the horns of the giraffe family consist of bone processes covered only by skin and hair; the horns of the bovine family also have a bone core, but are covered by a sheath, which is lifelong growth, and cannot be regenerated without bifurcation; and the horns of deer are periodically shed, regenerated once a year, and are called deer antlers during the growth stage, and its hair growth tissue is above the antler velvet, so it will grow in forks. When growth stops, the antler velvet calcifis into antlers and there is no horn sheath. Some animals with subhorned orders also do not have horns, such as musk and roe deer.
By comparing different types of ruminant genomes and up to 270 transcriptomes, the researchers found that sheep's horn and deer antler velvet have similar gene expression patterns, with their specifically highly expressed genes primarily recruited from genes expressed in bone, skin, brain, and testicular tissue. These highly expressed genes specific to the horn tissue, along with some rapidly evolving genes, are involved in the neurovertebral cell migration pathway, thus proposing for the first time from a genetic point of view that the horns of ruminants have the same cellular origin - head neurovertebral stem cells.
The study provides genetic evidence for the single evolutionary origin of ruminant horn, the theoretical basis for the breeding of hornless cattle and sheep, and the key target genes for the production of hornless cattle and sheep through gene editing. (End)