Li Kang, Huo Chunmao, Long Hong, Tang Ketong, Zhang Shibin
Zunyi Medical University, Zunyi, China.
Sci Rep. 2024 Dec 28;14(1):31480. doi: 10.1038/s41598-024-82975-7.
Worldwide, congenital deafness and pigmentation disorders impact millions with their diverse manifestations, and among these genetic conditions, mutations in the Microphthalmia-associated transcription factor (MITF: OMIM#156845) gene are notable for their profound effects on melanocyte development and auditory functions. This study reports a novel porcupine model exhibiting spontaneous deafness and pigmentation abnormalities reminiscent of human Waardenburg Syndrome Type 2 (WS2: OMIM#193510). Through phenotypic characterization, including coat color, skin, eye morphology, and auditory brainstem response (ABR) assessments, we identified hypopigmentation and complete deafness in mutant porcupines. To pinpoint the genetic basis, a breeding program was established, and Bulk Segregant Analysis (BSA) combined with RNA sequencing was conducted. Primers based on the identified candidate genes were designed for PCR amplification, followed by verification through Sanger sequencing. Through BSA analysis, we identified a total of 88 SNP and 336 InDel candidate sites. By annotating the Mitf gene, we obtained four unique transcript sequences. The SNP and InDel sites within the porcupine Mitf gene sequence, identified through BSA screening, were analyzed in conjunction with the gene's annotation results. This analysis revealed a specific mutation site, Mitf c.875_877delGAA p. (Arg217del), which was subsequently verified by Sanger sequencing. This naturally occurring Mitf mutation in porcupines provides a valuable model for studying the mechanisms underlying WS2 and exploring potential therapeutic strategies for deafness and pigmentation-related disorders.
在全球范围内，先天性耳聋和色素沉着障碍以其多样的表现形式影响着数百万人。在这些遗传疾病中，小眼症相关转录因子（MITF：OMIM#156845）基因的突变因其对黑素细胞发育和听觉功能的深远影响而备受关注。本研究报告了一种新型豪猪模型，该模型表现出自发性耳聋和色素沉着异常，类似于人类2型瓦登伯格综合征（WS2：OMIM#193510）。通过包括毛色、皮肤、眼睛形态和听觉脑干反应（ABR）评估在内的表型特征分析，我们在突变豪猪中发现了色素减退和完全耳聋的现象。为了确定遗传基础，我们建立了一个育种计划，并进行了混合分组分析法（BSA）与RNA测序相结合的研究。基于鉴定出的候选基因设计引物进行PCR扩增，随后通过桑格测序进行验证。通过BSA分析，我们总共鉴定出88个单核苷酸多态性（SNP）和336个插入缺失（InDel）候选位点。通过对Mitf基因进行注释，我们获得了四个独特的转录本序列。将通过BSA筛选鉴定出的豪猪Mitf基因序列中的SNP和InDel位点与该基因的注释结果相结合进行分析。该分析揭示了一个特定的突变位点，即Mitf c.875_877delGAA p.（Arg217del），随后通过桑格测序进行了验证。豪猪中这种自然发生的Mitf突变，为研究WS2的潜在机制以及探索耳聋和色素沉着相关疾病的潜在治疗策略提供了一个有价值的模型。
