Advances in single-cell RNA sequencing in the retina / 中华眼底病杂志

Retina is composed of a heterogeneous population of cell types, each with a unique biological function. Even if the same type of cells, due to genetic heterogeneity will lead to cell function differences. In the past, traditional molecular biological methods cannot resolve variations in their functional roles that arise from these differences, and some cells are difficult to define due to the lack of specific molecular markers or the scarcity of numbers, which hindered the understanding and research of these cells. With the development of biotechnology, single-cell RNA sequencing can analyze and resolve differences in single-cell transcriptome expression profiles, characterize intracellular population heterogeneity, identify new and rare cell subtypes, and more definitely define the characteristics of each cell type. It clarifies the origin, function, and variations in cell phenotypes. Other attributes include pinpointing both disease-related characteristics of cell subtypes and specific differential gene expression patterns, to deepen our understanding of the causes and progression of diseases, as well as to aid clinical diagnosis and targeted therapy.

A novel mutation T8821G in mitochondrial DNA may be associated with Leber's hereditary optic neuropathy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To report on clinical, genetic and molecular characterization of two Chinese families with Leber's hereditary optic neuropathy.</p><p><b>METHODS</b>Ophthalmological examinations have revealed variable severity and age at onset of visual loss among the probands and other matrilineal relatives of both families. The entire mitochondrial genome of the two probands was amplified with PCR in 24 overlapping fragments using sets of oligonucleotide primers.</p><p><b>RESULTS</b>The ophthalmological examinations showed that penetrance was 12.5% and 30.0% respectively in the two families. Sequence analysis of the complete mitochondrial genomes in these pedigrees has identified unreported homoplasmic T8821G mutation in the ATPase 6 gene and distinct sets of polymorphisms belonging to haplogroups M10a. The T8821G mutation has occurred at the extremely conserved nucleotide (conventional position 99) of the ATPase6. Thus, this mutation may alter structural formation of ATPase6, thereby leading to failure in the synthesis of ATP involved in visual impairment.</p><p><b>CONCLUSION</b>Above observations have suggested that the ATPase6 T8821G mutation may be involved in the pathogenesis of optic neuropathy in these families.</p>