Multiple Harvey-ras genes in the bovine genome

Area of Science:

• Molecular Biology
• Genetics
• Genomics

Background:

• The Harvey-ras (Ha-ras) gene family plays a crucial role in cellular signaling pathways.
• Understanding the structure and function of ras genes in different species, including cattle, is important for comparative genomics and disease research.

Purpose of the Study:

• To identify and characterize Harvey-ras (Ha-ras) genes within the bovine genome.
• To determine the structural organization, nucleotide sequences, and functional potential of these bovine Ha-ras genes.

Main Methods:

• Screening of a lambda phage-bovine DNA library using a viral Ha-ras probe.
• Hybridization and heteroduplex analysis with viral and human Ha-ras genes.
• Nucleotide sequencing and heteroduplex mapping to establish gene structure and identify coding regions.

Main Results:

• Three distinct bovine Ha-ras genes were identified: bovine Ha-ras 1, bovine Ha-ras 2, and c-Ha-ras 3.
• Bovine Ha-ras 1 and Ha-ras 2 exhibit typical exon-intron structures of c-Ha-ras genes but possess distinct nucleotide sequences and physical maps.
• C-Ha-ras 3 was identified as a pseudogene, lacking introns and analogous to human c-Ha-ras 2. Bovine Ha-ras 1 encodes a functional ras protein, while Ha-ras 2 has diverged significantly.

Conclusions:

• The bovine genome contains multiple Ha-ras gene family members with varying degrees of functional conservation.
• Bovine Ha-ras 1 represents a functional gene, whereas Ha-ras 2 shows divergence, and c-Ha-ras 3 is a pseudogene.
• These findings contribute to the understanding of ras gene evolution and diversity in mammals.