Evidence of dramatic sterility in F1 male hybrid catfish [male Clarias gariepinus (Burchell, 1822) × female C. macrocephalus (Günther, 1864)] resulting from the failure of homologous chromosome pairing in meiosis I

Consequence of Paradigm Shift with Repeat Landscapes in Reptiles: Powerful Facilitators of Chromosomal Rearrangements for Diversity and Evolution

“…In addition to genome size, TE mobilization and amplification of copy number can affect genome reorganization via non-homologous recombination, leading to diverse types of chromosomal rearrangements, including deletion, inversion, duplication, and translocation, or the emergence of neocentromere and centromere repositioning. This can result in changes in the host genome and diversity at the individual, population, or species level as a consequence of postzygotic reproductive isolation mechanisms [9,124]. In turn, this prevents the formation of fertile offspring through hybrid unviability, sterility, and/or breakdown after fertilization caused by differences in karyotypes and/or chromosome structure between the parental species, resulting in meiotic arrest and subsequent apoptosis of gametocytes [9,125,126].…”

“…This can result in changes in the host genome and diversity at the individual, population, or species level as a consequence of postzygotic reproductive isolation mechanisms [ 9 , 124 ]. In turn, this prevents the formation of fertile offspring through hybrid unviability, sterility, and/or breakdown after fertilization caused by differences in karyotypes and/or chromosome structure between the parental species, resulting in meiotic arrest and subsequent apoptosis of gametocytes [ 9 , 125 , 126 ]. In a broader context, TE-induced rearrangements contribute to lineage-specific evolution by inducing chromosomal-scale variation, regulation, or mutation of genes, ultimately leading to participation in speciation [ 127 , 128 , 129 , 130 ].…”

“…Evolutionary mechanisms include variation in chromosome size, composition, and number between and within species, which has been termed “stasipatric speciation” [ 5 ]. Such chromosomal variation is also associated with reproductive isolation and outbreeding depression [ 6 , 7 , 8 , 9 ]. Approximately 320 million years ago, amniotes diverged into two major lineages comprising Synapsida, including all living mammals, and Sauropsida, including all extant non-avian reptilian and avian species [ 10 , 11 , 12 , 13 ].…”

An Investigation of ZZ/ZW and XX/XY Sex Determination Systems in North African Catfish (Clarias gariepinus, Burchell, 1822)

“…They now represent more than 90% of catfish production in Thailand ( Na-Nakorn et al, 2004a ). The F 1 hybrids are physically more vigorous than either parental species, but their mass production has been limited by reproductive failure ( Koolboon et al, 2014 ; Ponjarat et al, 2019 ). Ponjarat et al (2019) asserted that hybrid dysgenesis between the bighead catfish and North African catfish is caused by karyotypic and genomic differences, resulting in meiotic arrest and subsequent apoptosis of gametocytes.…”

“…The F 1 hybrids are physically more vigorous than either parental species, but their mass production has been limited by reproductive failure ( Koolboon et al, 2014 ; Ponjarat et al, 2019 ). Ponjarat et al (2019) asserted that hybrid dysgenesis between the bighead catfish and North African catfish is caused by karyotypic and genomic differences, resulting in meiotic arrest and subsequent apoptosis of gametocytes. However, the F 1 hybrid can occasionally cross-breed in captivity, whereby the female hybrids are fertile, with the potential to produce large numbers of backcross progeny that shows fertility and low embryo mortality, whereas the male hybrids are sterile ( Na-Nakorn et al, 2004b ; Abol-Munafi et al, 2006 ).…”