TY - JOUR A1 - Aga-Barfknecht, Heja A1 - Hallahan, Nicole A1 - Gottmann, Pascal A1 - Jähnert, Markus A1 - Osburg, Sophie A1 - Schulze, Gunnar A1 - Kamitz, Anne A1 - Arends, Danny A1 - Brockmann, Gudrun A1 - Schallschmidt, Tanja A1 - Lebek, Sandra A1 - Chadt, Alexandra A1 - Al-Hasani, Hadi A1 - Joost, Hans-Georg A1 - Schürmann, Annette A1 - Vogel, Heike T1 - Identification of novel potential type 2 diabetes genes mediating beta-cell loss and hyperglycemia using positional cloning JF - Frontiers in genetics N2 - Type 2 diabetes (T2D) is a complex metabolic disease regulated by an interaction of genetic predisposition and environmental factors. To understand the genetic contribution in the development of diabetes, mice varying in their disease susceptibility were crossed with the obese and diabetes-prone New Zealand obese (NZO) mouse. Subsequent whole-genome sequence scans revealed one major quantitative trait loci (QTL),Nidd/DBAon chromosome 4, linked to elevated blood glucose and reduced plasma insulin and low levels of pancreatic insulin. Phenotypical characterization of congenic mice carrying 13.6 Mbp of the critical fragment of DBA mice displayed severe hyperglycemia and impaired glucose clearance at week 10, decreased glucose response in week 13, and loss of beta-cells and pancreatic insulin in week 16. To identify the responsible gene variant(s), further congenic mice were generated and phenotyped, which resulted in a fragment of 3.3 Mbp that was sufficient to induce hyperglycemia. By combining transcriptome analysis and haplotype mapping, the number of putative responsible variant(s) was narrowed from initial 284 to 18 genes, including gene models and non-coding RNAs. Consideration of haplotype blocks reduced the number of candidate genes to four (Kti12,Osbpl9,Ttc39a, andCalr4) as potential T2D candidates as they display a differential expression in pancreatic islets and/or sequence variation. In conclusion, the integration of comparative analysis of multiple inbred populations such as haplotype mapping, transcriptomics, and sequence data substantially improved the mapping resolution of the diabetes QTLNidd/DBA. Future studies are necessary to understand the exact role of the different candidates in beta-cell function and their contribution in maintaining glycemic control. KW - type 2 diabetes KW - beta-cell loss KW - insulin KW - positional cloning KW - transcriptomics KW - haplotype Y1 - 2020 U6 - https://doi.org/10.3389/fgene.2020.567191 SN - 1664-8021 VL - 11 PB - Frontiers Media CY - Lausanne ER -