Yáñez-Carrillo Patricia, Robledo-Márquez Karina A, Ramírez-Zavaleta Candy Y, De Las Peñas Alejandro, Castaño Irene
División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, San Luis Potosí, Mexico.
División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), San Luis Potosí, San Luis Potosí, Mexico.
Rev Iberoam Micol. 2014 Jan-Mar;31(1):30-4. doi: 10.1016/j.riam.2013.09.016. Epub 2013 Nov 16.
Candida glabrata, a haploid and opportunistic fungal pathogen that has not known sexual cycle, has conserved the majority of the genes required for mating and cell type identity. The C. glabrata genome contains three mating-type-like loci called MTL1, MTL2 and MTL3. The three loci encode putative transcription factors, a1, α1 and α2 that regulate cell type identity and sexual reproduction in other fungi like the closely related Saccharomyces cerevisiae. MTL1 can contain either a or α information. MTL2, which contains a information and MTL3 with α information, are relatively close to two telomeres. MTL1 and MTL2 are transcriptionally active, while MTL3 is subject to an incomplete silencing nucleated at the telomere that depends on the silencing proteins Sir2, Sir3, Sir4, yKu70/80, Rif1, Rap1 and Sum1. C. glabrata does not seem to maintain cell type identity, as cell type-specific genes are expressed regardless of the type (or even absence) of mating information. These data highlight important differences in the control of mating and cell type identity between the non-pathogenic yeast S. cerevisiae and C. glabrata, which might explain the absence of a sexual cycle in C. glabrata. The fact that C. glabrata has conserved the vast majority of the genes involved in mating might suggest that some of these genes perhaps have been rewired to control other processes important for the survival inside the host as a commensal or as a human pathogen. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).
光滑念珠菌是一种单倍体且具有机会致病性的真菌病原体，其不存在已知的有性生殖周期，但保留了交配和细胞类型识别所需的大多数基因。光滑念珠菌基因组包含三个类似交配型的基因座，称为MTL1、MTL2和MTL3。这三个基因座编码假定的转录因子a1、α1和α2，它们在其他真菌（如密切相关的酿酒酵母）中调节细胞类型识别和有性生殖。MTL1可以包含a或α信息。包含a信息的MTL2和包含α信息的MTL3相对靠近两个端粒。MTL1和MTL2具有转录活性，而MTL3受到端粒起始的不完全沉默的影响，这种沉默依赖于沉默蛋白Sir2、Sir3、Sir4、yKu70/80、Rif1、Rap1和Sum1。光滑念珠菌似乎并不维持细胞类型识别，因为无论交配信息的类型（甚至不存在）如何，细胞类型特异性基因都会表达。这些数据突出了非致病性酵母酿酒酵母和光滑念珠菌在交配控制和细胞类型识别方面的重要差异，这可能解释了光滑念珠菌不存在有性生殖周期的原因。光滑念珠菌保留了绝大多数参与交配的基因这一事实可能表明，其中一些基因可能已被重新连接以控制作为共生菌或人类病原体在宿主体内存活的其他重要过程。本手稿是在“第五届国际研讨会：人类致病真菌研究的分子遗传学方法”（2012年，墨西哥瓦哈卡）上发表的系列作品的一部分。
