INRA, UMR1313, Unité de Génétique Animale et Biologie Intégrative, Jouy-en-Josas, France.
PLoS One. 2012;7(1):e30073. doi: 10.1371/journal.pone.0030073. Epub 2012 Jan 17.
Natural mutations in the LIPH gene were shown to be responsible for hair growth defects in humans and for the rex short hair phenotype in rabbits. In this species, we identified a single nucleotide deletion in LIPH (1362delA) introducing a stop codon in the C-terminal region of the protein. We investigated the expression of LIPH between normal coat and rex rabbits during critical fetal stages of hair follicle genesis, in adults and during hair follicle cycles. Transcripts were three times less expressed in both fetal and adult stages of the rex rabbits than in normal rabbits. In addition, the hair growth cycle phases affected the regulation of the transcription level in the normal and mutant phenotypes differently. LIPH mRNA and protein levels were higher in the outer root sheath (ORS) than in the inner root sheath (IRS), with a very weak signal in the IRS of rex rabbits. In vitro transfection shows that the mutant protein has a reduced lipase activity compared to the wild type form. Our results contribute to the characterization of the LIPH mode of action and confirm the crucial role of LIPH in hair production.
自然突变的 LIPH 基因被证明是导致人类毛发生长缺陷和兔子雷克斯短毛表型的原因。在这种物种中，我们在 LIPH 中发现了一个单一核苷酸缺失（1362delA），在蛋白质的 C 末端区域引入了一个终止密码子。我们研究了 LIPH 在毛囊发生的关键胎儿阶段、成年期和毛囊周期期间在正常皮毛和雷克斯兔子之间的表达。在雷克斯兔子的胎儿和成年阶段，转录物的表达水平比正常兔子低三倍。此外，毛发生长周期阶段对正常和突变表型的转录水平调节有不同的影响。LIPH mRNA 和蛋白水平在外根鞘（ORS）中高于内根鞘（IRS），雷克斯兔子的 IRS 中信号非常弱。体外转染表明，突变蛋白的脂肪酶活性比野生型形式降低。我们的研究结果有助于描述 LIPH 的作用模式，并证实了 LIPH 在毛发产生中的关键作用。
