International Journal of Molecular Ecology and Conservation, 2025, Vol.15, No.1, 19-29 http://ecoevopublisher.com/index.php/ijmec 22 through behavior (such as curling up, reducing heat loss) and metabolic regulation (such as reducing basal metabolic rate). In goats, FGF5 has been identified as a major gene affecting the length of villi. Some goats in high-altitude cold areas carry FGF5 loss-of-function mutations, which grow longer villi to keep out the cold (Wu et al., 2024). In addition, EDA2R and KRT family genes are also involved in the development of hair and skin, and are selected in the adaptation of goat coat. In addition to climatic factors, pathogen pressure in the environment is also an important selection pressure driving the evolutionary adaptation of goats. Goats have to deal with a variety of parasites, bacteria and viruses in the wild and on farms, and have evolved strong immune resistance (Luo et al., 2024). For example, during the domestication of goats, a galectin gene cluster (LGALS9 and its analogs) associated with immune response was repeated and expanded, resulting in three additional copies of LGALS9-like genes in domestic goats compared to wild goats (Bian et al., 2024). Another aspect worth paying attention to is reproductive adaptation. During the domestication and breeding of goats, high fertility is often favored. In sheep, the well-known intron deletion of the BMPR1B gene (FecB mutation) can increase the number of ovulations and the number of lambs. Similarly, a deletion mutation (about ~9 kb in length) of the BMPR1B gene was found in goats to affect reproductive traits (Yang et al., 2024). 3 Research Progress on Horizontal Gene Transfer (HGT) in Goat Adaptation 3.1 Progress in detection and research methods of HGT In recent years, researchers have developed many bioinformatics tools to assist HGT detection. For example, software such as HGTector, Horizoner, and PHYLOTIC combine abnormal sequence screening and phylogenetic tree construction to perform HGT scanning on massive genomic data (Carpanzano et al., 2022). Some processes adopt the "screening first and then verification" strategy: first screen out suspected exogenous genes based on sequence similarity, and then verify the relationship between genes in different species through phylogenetic tree analysis (Schwarzerova et al., 2024). It should be emphasized that with the increasing size of genome databases, species sampling bias may affect the accuracy of HGT detection (Huang et al., 2017). To this end, new methods have begun to introduce machine learning algorithms to perform pattern recognition on sequence features, which improves the sensitivity to HGT "traces" (Wijaya et al., 2025). In view of the particularity of vertebrate genomes (isolation of somatic cells and reproductive system, low frequency of HGT), researchers have also adjusted their analysis ideas. Since most HGT events occur between microorganisms or viruses and hosts, viral vectors are often regarded as an important pathway for eukaryotic HGT (Irwin et al., 2022). Therefore, scientists also pay attention to the traces of viral sequences or transposons in the host genome in their research. The appearance of these sequences often means the introduction of horizontal genes in the past (Verneret et al., 2025). In addition, the combination of multi-omics data is also helpful: through transcriptome and proteome, it can be verified whether the suspected HGT gene is expressed and functions in the host, thereby distinguishing true HGT integrated genes from possible experimental/sequencing contamination. 3.2 Examples of HGT in goats and their closely related species In ruminants, researchers have identified a unique syncytin gene, named Syncytin-Rum1, which is highly conserved in advanced ruminants such as cattle, sheep, and antelopes, and is presumed to have been integrated into the genome of a common ancestor about 30 million years ago (Cornelis et al., 2013). Ruminants such as goats have achieved innovations in placental structure and function by "borrowing" genes from ancient viruses to adapt to their special reproductive needs. , BovB sequences are widely present in unrelated mammals such as ruminants, horses, and kangaroos, but are missing in some more closely related species, which is consistent with the characteristics of cross-kingdom HGT (Huang et al., 2017). For goats, their genomes also carry BovB elements. Since BovB can be inserted at different locations in the genome, its impact on the goat genome structure cannot be ignored. Goats are typical ruminants, and rumen microorganisms are crucial for their digestion of crude fiber feed. Ricard et al. (2006) sequenced the ESTs of rumen ciliates and found that rumen ciliates acquired many enzyme genes
RkJQdWJsaXNoZXIy MjQ4ODYzNA==