# The TBXT Gene and Brachyury Protein Are Differentially Expressed During the Early Embryonic Development of Hu and Hulunbuir Sheep

## TL;DR

This study compares how the TBXT gene and Brachyury protein are expressed in two sheep breeds during early development, revealing differences in their regulation of tail and organ growth.

## Contribution

The study identifies breed-specific spatiotemporal expression patterns of TBXT and Brachyury in sheep embryos, offering insights into molecular regulation of tail development.

## Key findings

- TBXT gene expression varies in location and timing between Hulunbuir and Hu sheep embryos.
- Brachyury protein shows breed-specific expression in organs like the heart, gut, and tail bud.
- Differences in gene and protein regulation suggest distinct molecular pathways for tail and organ development in the two breeds.

## Abstract

In this study, SweAMI FISH fluorescence in situ hybridization and immunofluorescence were used to analyze the spatiotemporal expression characteristics of the TBXT gene and Brachyury protein in 16-day-old Hulunbuir sheep embryos and 19-day-old Hu sheep embryos and to explore their regulatory effects on the development of sheep tails and related organs. The study showed the following: At 16 days of embryonic age, the TBXT gene was concentratedly expressed in the heart, somites, neural tube, and mesonephros of both sheep breeds; at 19 days of embryonic age, it was concentratedly expressed in the limb ectoderm and tail bud of Hulunbuir sheep, and in the midgut and tail bud of Hu sheep. At 16 days of embryonic age, the BRACHYURY protein was concentratedly expressed in the neural tube, somites, brain vesicles, and mesonephros of both sheep breeds; at 19 days of embryonic age, it was concentratedly expressed in the heart and hindgut of Hulunbuir sheep, and in the tail bud and hindgut of Hu sheep. In summary, this shows that there are differences in the temporal and spatial expressions of the TBXT gene and BRACHYURY protein between the two sheep breeds. There are also site-specific and time-specific differences in the regulation of the above genes and proteins during tail and related organ development between the two breeds, which confirms that the molecular regulation pathways of tail and related organ development are different between the two breeds. This study provides an experimental basis for screening molecular markers related to goat tail development and breed improvement.