Karos M, Chang Y C, McClelland C M, Clarke D L, Fu J, Wickes B L, Kwon-Chung K J
Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Bacteriol. 2000 Nov;182(21):6222-7. doi: 10.1128/JB.182.21.6222-6227.2000.
In this study we investigated the relationship between the MATalpha locus of Cryptococcus neoformans and several MATalpha-specific mitogen-activated protein (MAP) kinase signal transduction cascade genes, including STE12alpha, STE11alpha, and STE20alpha. To resolve the location of the genes, we screened a cosmid library of the MATalpha strain B-4500 (JEC21), which was chosen for the C. neoformans genome project. We isolated several overlapping cosmids spanning a region of about 71 kb covering the entire MATalpha locus. It was found that STE12alpha, STE11alpha, and STE20alpha are imbedded within the locus rather than closely linked to the locus. Furthermore, three copies of MFalpha, the mating type alpha-pheromone gene, a MATalpha-specific myosin gene, and a pheromone receptor (CPRalpha) were identified within the locus. We created a physical map, based on the restriction enzyme BamHI, and identified both borders of the MATalpha locus. The MATalpha locus of C. neoformans is approximately 50 kb in size and is one of the largest mating type loci reported among fungi with a one-locus, two-allele mating system.
在本研究中，我们调查了新型隐球菌MATalpha位点与几个MATalpha特异性丝裂原活化蛋白（MAP）激酶信号转导级联基因之间的关系，这些基因包括STE12alpha、STE11alpha和STE20alpha。为了确定这些基因的位置，我们筛选了MATalpha菌株B - 4500（JEC21）的黏粒文库，该菌株是为新型隐球菌基因组计划而挑选的。我们分离出了几个重叠的黏粒，它们跨越了一个约71 kb的区域，覆盖了整个MATalpha位点。结果发现，STE12alpha、STE11alpha和STE20alpha嵌入在位点内，而不是与该位点紧密连锁。此外，在位点内还鉴定出了三个拷贝的MFalpha，即交配型α-信息素基因、一个MATalpha特异性肌球蛋白基因和一个信息素受体（CPRalpha）。我们基于限制性内切酶BamHI构建了一个物理图谱，并确定了MATalpha位点的两个边界。新型隐球菌的MATalpha位点大小约为50 kb，是具有一位点、双等位基因交配系统的真菌中报道的最大交配型位点之一。
