Despite the progress of the chicken (Gallus gallus) genome sequencing project, the centromeric sequences of most macrochromosomes remain unknown. This makes it difficult to determine centromere positions in the genome sequence assembly. Using giant lampbrush chromosomes from growing oocytes, we analyzed in detail the pericentromeric region of chicken chromosome 3. Without knowing the DNA sequence, the centromeres at the lampbrush stage are detectable by immunostaining with antibodies against cohesin subunits. Immunostaining for cohesin followed by FISH with 23 BAC clones, covering the region from 0 to 23 Mb on chicken chromosome 3 (GGA3), allowed us to map the GGA3 centromere between BAC clones WAG38P15 and WAG54M22 located at position 2.3 and 2.5 Mb, respectively. This corresponds to the gap between 2 supercontigs at the 2.4-Mb position in the current GGA3 sequence assembly (build 2.1). Furthermore, we have determined that the current putative centromeric gap at position 11.6-13.1 Mb corresponds in fact to a long cluster of tandem chicken erythrocyte nuclear membrane repeats (CNM).
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http://dx.doi.org/10.1159/000314923 | DOI Listing |
Vet Sci
January 2025
Department of Genetics and Hereditary Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 400372 Cluj-Napoca, Romania.
Birds are inherently social creatures that rely on pairing to enhance their well-being. Since many bird species lack obvious physical differences between females and males, sex identification is essential for ensuring their welfare. Additionally, early determination of the sexes of birds is crucial for their breeders, especially considering that most companion birds do not display clear sexual characteristics.
View Article and Find Full Text PDFJ Anim Sci Biotechnol
January 2025
Frontiers Science Center for Molecular Design Breeding (MOE), State Key Laboratory of Animal Biotech Breeding, and National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
Background: Chickens and ducks are vital sources of animal protein for humans. Recent pangenome studies suggest that a single genome is insufficient to represent the genetic information of a species, highlighting the need for more comprehensive genomes. The bird genome has more than tens of microchromosomes, but comparative genomics, annotations, and the discovery of variations are hindered by inadequate telomere-to-telomere level assemblies.
View Article and Find Full Text PDFJ Mol Evol
January 2025
Computational Evolutionary Genomics Lab, Department of Biological Sciences, IISER Bhopal, Bhauri, Madhya Pradesh, India.
The diversity in dermal pigmentation and plumage color among domestic chickens is striking, with Black Bone Chickens (BBC) particularly notable for their intense melanin hyperpigmentation. This unique trait is driven by a complex chromosomal rearrangement on chromosome 20 at the Fm locus, resulting in the overexpression of the EDN3 (a gene central to melanocyte regulation). In contrast, the inhibition of dermal pigmentation is regulated by the Id locus.
View Article and Find Full Text PDFSci Data
January 2025
Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, Republic of Korea.
This study presents the first chromosome-level genome assembly of the Korean long-tailed chicken (KLC), a unique breed of Gallus gallus known as Ginkkoridak. Our assembly achieved a super contig N50 of 5.7 Mbp and a scaffold N50 exceeding 90 Mb, with a genome completeness of 96.
View Article and Find Full Text PDFAnimals (Basel)
December 2024
State Key Laboratory of Swine and Poultry Breeding Industry, Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
Retinoic acid (RA) plays a critical role in initiating meiosis in primordial germ cells (PGC), yet the specific mechanisms of its interaction with PGC remain unclear. In this study, we used an in vitro feeder-free culture system with chicken PGC as a model to explore the mechanisms by which RA induces the entry of PGC into meiosis. Results demonstrated that exogenous RA treatment altered the cell cycle distribution of PGC, significantly increasing the proportion of cells in the G1 phase and decreasing those in the G2 phase, suggesting that RA may promote the transition of PGC from proliferation to differentiation.
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