Choi Yeon-Jae, Jung Sujin, Eom Hyerang, Hoang Thimen, Han Hui-Gang, Kim Sinil, Ro Hyeon-Su
Department of BioMedical Bigdata (BK21), Research Institute of Life Sciences, Gyeongsang National University, Jinju 52828, Republic of Korea.
J Fungi (Basel). 2023 Feb 21;9(3):284. doi: 10.3390/jof9030284.
Karyotyping in is crucial for both the isolation of homokaryotic strains and the confirmation of dikaryon establishment. For the verification of the karyotype, the mating type loci of two homokaryotic strains, H39 and H97, were analyzed through comparative sequence analysis. The two loci showed major differences in two sequence regions designated as Region 1 and Region 2. H97 had a putative DNA transposon in Region 1 that had target site duplications (TSDs), terminal inverted repeats (TIRs), and a loop sequence, in contrast to H39, which only had the insertional target sequence. Homologous sequences of the transposon were discovered in the two different chromosomes of H97 and in one of H39, all of which have different TSDs but share high sequence homology in TIR. Region 2 shared three consensus sequences between H97 and H39. However, it was only from H97 that a large insertional sequence of unknown origin was discovered between the first and second consensus sequences. The difference in length in Region 1, employed for the verification of the mating type, resulted in the successful verification of mating types in the heterokaryotic and homokaryotic strains. This length difference enables the discrimination between homo- and heterokaryotic spores by PCR. The present study suggests that the mating type locus in H97 has evolved through transposon insertion, allowing the discrimination of the mating type, and thus the nuclear type, between H97 and H39.
核型分析对于单核菌株的分离和双核体建立的确认都至关重要。为了验证核型，通过比较序列分析对两个单核菌株H39和H97的交配型位点进行了分析。这两个位点在指定为区域1和区域2的两个序列区域显示出主要差异。与仅具有插入靶序列的H39相比，H97在区域1中有一个推定的DNA转座子，其具有靶位点重复（TSD）、末端反向重复（TIR）和一个环序列。在H97的两条不同染色体以及H39的一条染色体中发现了转座子的同源序列，所有这些序列都具有不同的TSD，但在TIR中具有高度的序列同源性。区域2在H97和H39之间共有三个共有序列。然而，仅在H97中，在第一个和第二个共有序列之间发现了一个未知来源的大插入序列。用于验证交配型的区域1中的长度差异导致成功验证了异核和单核菌株中的交配型。这种长度差异使得能够通过PCR区分同核和异核孢子。本研究表明，H97中的交配型位点通过转座子插入而进化，从而能够区分H97和H39之间的交配型，进而区分核型。
