Banding cytogenetics of the Barbary partridge Alectoris barbara and the Chukar partridge Alectoris chukar (Phasianidae): a large conservation with Domestic fowl Gallus domesticus revealed by high resolution chromosomes

Abstract

The development of avian cytogenetics is significantly behind that of mammals. In fact, since the advent of cytogenetic techniques, fewer than 1500 karyotypes have been established. The Barbary partridge Alectoris barbara Bonnaterre, 1790 is a bird of economic interest but its genome has not been studied so far. This species is endemic to North Africa and globally declining. The Chukar partridge Alectoris chukar Gray, 1830 is an introduced species which shares the same habitat area as the Barbary partridge and so there could be introgressive hybridisation. A cytogenetic study has been initiated in order to contribute to the Barbary partridge and the Chukar partridge genome analyses. The GTG, RBG and RHG-banded karyotypes of these species have been described. Primary fibroblast cell lines obtained from embryos were harvested after simple and double thymidine synchronisation. The first eight autosomal pairs and Z sex chromosome have been described at high resolution and compared to those of the domestic fowl Gallus domesticus Linnaeus, 1758. The diploid number was established as 2n = 78 for both partridges, as well as for most species belonging to the Galliformes order, underlying the stability of chromosome number in avian karyotypes. Wide homologies were observed for macrochromosomes and gonosome except for chromosome 4, 7, 8 and Z which present differences in morphology and/or banding pattern. Neocentromere occurrence was suggested for both partridges chromosome 4 with an assumed paracentric inversion in the Chukar partridge chromosome 4. Terminal inversion in the long arm of the Barbary partridge chromosome Z was also found. These rearrangements confirm that the avian karyotypes structure is conserved interchromosomally, but not at the intrachromosomal scale.

Banding cytogenetics of chimeric hybrids Coturnix coturnix × Coturnix japonica and comparative analysis with the domestic fowl

“…The high sensibility observed in cells cultures of wild quail corroborate with the vulnerability of this species in breeding areas unlike the Japanese quail because of its easy practical prolificacy in captivity (Caballero de la Calle et Peña Montañés 1997, personal communication of the Tlemcen Hunting Centre). This is the case for the Barbary and Chukar partridges ( Ouchia-Benissad and Ladjali-Mohammedi 2018 ).…”

“…The diploid number of 2N=78 estimated in Common quail and then in Japanese quail, emphasizes the exceptional conservation of karyotypes in the order of Galliformes ( Ohno et al 1964 , Takagi and Sasaki 1974 , Stock and Bunch 1982 , Arruga et al 1996 , Shibusawa et al 2004 , Ishishita et al 2014 , Ouchia-Benissad and Ladjali-Mohammedi 2018 ). This is the case for the domestic fowl Gallus gallus domesticus , too ( Ladjali 1994 ).…”

“…This was already reported by Galkina et al (2006) showing a perfect conservation of Chicken BAC clones order on Japanese quail chromosome 4. In fact, centromeres appear to be formed de novo during the evolution of Galliformes karyotypes ( Kasai et al 2003 , Galkina et al 2006 , Skinner et al 2009 , Ouchia-Benissad and Ladjali-Mohammedi 2018 ).…”

“…Although high resolution molecular techniques are well advanced, chromosome banding remains an effective method for delineating chromosome homologies between phylogenetically related species. Indeed, banding colorations allow participation, in an important way, in the studies of taxonomy and phylogenetics and reveal the ancestral chromosome rearrangements of vertebrates ( Rumpler and Rumpler 1976 , Yunis et al 1982 , Bouayed 2004 , Muffato 2010 , Ouchia-Benissad and Ladjali-Mohammedi 2018 ).…”

Banding cytogenetics of the vulnerable species Houbara bustard (Otidiformes) and comparative analysis with the Domestic fowl

“…Chromosome Z that is metacentric in chicken appears to be submetacentric in many other species of Galliformes (Nanda et al 2008). Also, a terminal inversion has been reported on chromosome Z of Chukar partridge (Ouchia-Benissad and Ladjali-Mohammedi 2018).…”