Meiotic peculiarities in hybrid buffalo

Area of Science:

• Animal Genetics
• Reproductive Biology
• Cytogenetics

Background:

• Water buffalo (Bubalis bubalis) comprise two varieties with distinct karyotypes: Bubalis bubalis var. bubalis (2n=50) and Bubalis bubalis var. carabao (2n=48).
• Fertile F1 hybrids between these varieties are expected to have a 2n=49 karyotype, bridging the chromosomal difference.

Purpose of the Study:

• To investigate the meiotic behavior in hybrid water buffalo bulls.
• To examine the karyotypes and chromosomal pairing during meiosis in F1 hybrids.

Main Methods:

• Karyotyping was performed on leukocyte cultures and testicular biopsy samples from 10 hybrid water buffalo bulls.
• Meiosis was analyzed, specifically focusing on diakinesis (metaphase I) and synapsis stages.

Main Results:

• Five bulls exhibited a 2n=50 karyotype, while the other five had a 2n=49 karyotype.
• Multivalent chromosome associations were observed in diakinesis cells of bulls with the 2n=49 karyotype.
• Synapsis, the pairing of homologous chromosomes, was present in bulls of both karyotypes.

Conclusions:

• The presence of multivalent chromosomes in 2n=49 hybrid water buffalo bulls suggests chromosomal rearrangements or heterozygosity.
• Meiotic processes, including synapsis, occur in these fertile hybrids despite karyotypic differences.
• Further research is warranted to understand the implications of these meiotic findings on reproductive fitness and genetic diversity in water buffalo populations.