Publication Date:
2008-01-11
Description:
Sex determination in fungi is controlled by a small, specialized region of the genome in contrast to the large sex-specific chromosomes of animals and some plants. Different gene combinations reside at these mating-type (MAT) loci and confer sexual identity; invariably they encode homeodomain, alpha-box, or high mobility group (HMG)-domain transcription factors. So far, MAT loci have been characterized from a single monophyletic clade of fungi, the Dikarya (the ascomycetes and basidiomycetes), and the ancestral state and evolutionary history of these loci have remained a mystery. Mating in the basal members of the kingdom has been less well studied, and even their precise taxonomic inter-relationships are still obscure. Here we apply bioinformatic and genetic mapping to identify the sex-determining (sex) region in Phycomyces blakesleeanus (Zygomycota), which represents an early branch within the fungi. Each sex allele contains a single gene that encodes an HMG-domain protein, implicating the HMG-domain proteins as an earlier form of fungal MAT loci. Additionally, one allele also contains a copy of a unique, chromosome-specific repetitive element, suggesting a generalized mechanism for the earliest steps in the evolution of sex determination and sex chromosome structure in eukaryotes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Idnurm, Alexander -- Walton, Felicia J -- Floyd, Anna -- Heitman, Joseph -- England -- Nature. 2008 Jan 10;451(7175):193-6. doi: 10.1038/nature06453.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18185588" target="_blank"〉PubMed〈/a〉
Keywords:
Alleles
;
Amino Acid Sequence
;
Chromosomes, Fungal/genetics
;
Computational Biology
;
Fertility/genetics
;
Fungal Proteins/chemistry/genetics
;
Fungi/classification/*genetics
;
Genes, Fungal/*genetics
;
Genes, Mating Type, Fungal/genetics
;
HMG-Box Domains
;
Heterozygote
;
High Mobility Group Proteins/chemistry/genetics
;
Molecular Sequence Data
;
*Phylogeny
;
Recombination, Genetic/genetics
;
Repetitive Sequences, Nucleic Acid/genetics
;
*Sex
;
*Sex Determination Processes
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
