title: Androgenetic development of X- and Y-chromosome bearing haploid rainbow trout embryos.
abstract: Haploid fish embryos are important in studies regarding role of the recessive traits during early ontogeny. In fish species with the male heterogamety, androgenetic haploid embryos might be also useful tool in studies concerning role of the sex chromosomes during an embryonic development. Morphologically differentiated X and Y chromosomes have been found in a limited number of fish species including rainbow trout (Oncorhynchus mykiss Walbaum 1792). To evaluate role of the sex chromosomes during rainbow trout embryonic development, survival of the androgenetic haploids in the presence of X or Y sex chromosomes has been examined. Androgenetic haploid rainbow trout were produced by fertilization of X-irradiated eggs with spermatozoa derived from the normal males (XY) and neomales, that is, sex-reversed females (XX) to produce X- and Y-bearing haploids, and all X-bearing haploids, respectively. Survival rates of the androgenetic progenies of normal males and neomales examined during embryogenesis and at hatching did not differ significantly. However, all haploids died within next few days after hatching. Cytogenetic analysis of the androgenetic embryos confirmed their haploid status. Moreover, apart from the intact paternal chromosomes, residues of the irradiated maternal chromosomes observed as chromosome fragments were identified in some of the haploids. Provided results suggested that rainbow trout X and Y chromosomes despite morphological and genetic differences are at the early stage of differentiation and still share genetic information responsible for the proper embryonic development.
authors.affiliation: Department of Molecular Evolution, University of Gdansk, ul. Wita Stwosza 59, 80-308 Gdansk, Poland.
authors.forename: Oliwia
authors.initials: O
authors.lastname: Michalik
authors.affiliation: Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland.
authors.forename: Radosław K
authors.initials: RK
authors.lastname: Kowalski
authors.affiliation: Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-748 Olsztyn, Poland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Judycka
authors.affiliation: Department of Salmonid Research, Inland Fisheries Institute in Olsztyn, Rutki, 83-330 Zukowo, Poland.
authors.forename: Rafał
authors.initials: R
authors.lastname: Rożyński
authors.affiliation: Department of Salmonid Research, Inland Fisheries Institute in Olsztyn, Rutki, 83-330 Zukowo, Poland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Dobosz
authors.affiliation: Department of Marine Biology and Ecology, Institute of Oceanography, University of Gdansk, Al. M. Piłsudskiego 46, 81-378 Gdynia, Poland. Electronic address: konrad.ocalewicz@ug.edu.pl.
authors.forename: Konrad
authors.initials: K
authors.lastname: Ocalewicz
mesh_terms: D000818:Animals; D020732:Cytogenetic Analysis; D004625:Embryo, Nonmammalian / Q000502:physiology*; D047108:Embryonic Development; D005260:Female; D006238:Haploidy; D008297:Male; D017686:Oncorhynchus mykiss / Q000196:embryology*; D012100:Reproduction, Asexual / Q000502:physiology; D014960:X Chromosome; D014998:Y Chromosome
keywords: Androgenesis; Neomales; Reproduction; Salmonidae; Sex chromosome