scholarly journals Simple inheritance of a complex trait: figured wood in curly birch is caused by one semi-dominant and lethal Mendelian factor?

2017 ◽  
Vol 47 (7) ◽  
pp. 991-995 ◽  
Author(s):  
K. Kärkkäinen ◽  
A. Viherä-Aarnio ◽  
P. Vakkari ◽  
R. Hagqvist ◽  
K. Nieminen

Even though individuals with a deviant morphology have been elemental in genetics of model species, they have thus far been largely ignored in the studies of forest trees. Here we studied the inheritance of curly-grained and brown-figured wood phenotype in curly birch (Betula pendula var. carelica (Mercklin) Hämet-Ahti). In addition of the figured wood, curly birches display reduced and aberrant growth, indicating that the causative locus (loci) is (are) vital for normal tree development. To explore the genetic basis of this mutation, we studied the inheritance of the curly birch phenotype in a progeny trial (crosses between curly birch parent trees, between curly and normal phenotypes, and from selfings of curly trees). Based on the external morphology, the phenotypes of 11-year-old progeny trees were scored as either curly or wild. Based on the phenotypic segregation ratios, we postulate a simple Mendelian inheritance model for curliness: (i) a one-locus, two-allele model in which the allele coding for curly phenotype is dominant over the allele coding for normal phenotype and (ii) the semi-dominant curly allele is lethal when homozygous. We expect that further studies on the molecular genetic basis of the curly birch phenotype will provide valuable information on the developmental pathways involved in wood formation.

2005 ◽  
Vol 26 (2) ◽  
pp. 251-282 ◽  
Author(s):  
Héctor F. Escobar-Morreale ◽  
Manuel Luque-Ramírez ◽  
José L. San Millán

The genetic mechanisms underlying functional hyperandrogenism and the polycystic ovary syndrome (PCOS) remain largely unknown. Given the large number of genetic variants found in association with these disorders, the emerging picture is that of a complex multigenic trait in which environmental influences play an important role in the expression of the hyperandrogenic phenotype. Among others, genomic variants in genes related to the regulation of androgen biosynthesis and function, insulin resistance, and the metabolic syndrome, and proinflammatory genotypes may be involved in the genetic predisposition to functional hyperandrogenism and PCOS. The elucidation of the molecular genetic basis of these disorders has been burdened by the heterogeneity in the diagnostic criteria used to define PCOS, the limited sample size of the studies conducted to date, and the lack of precision in the identification of ethnic and environmental factors that trigger the development of hyperandrogenic disorders. Progress in this area requires adequately sized multicenter collaborative studies after standardization of the diagnostic criteria used to classify hyperandrogenic patients, in whom modifying environmental factors such as ethnicity, diet, and lifestyle are identified with precision. In addition to classic molecular genetic techniques such as linkage analysis in the form of a whole-genome scan and large case-control studies, promising genomic and proteomic approaches will be paramount to our understanding of the pathogenesis of functional hyperandrogenism and PCOS, allowing a more precise prevention, diagnosis, and treatment of these prevalent disorders.


PLoS ONE ◽  
2016 ◽  
Vol 11 (11) ◽  
pp. e0164359 ◽  
Author(s):  
Luis Zea ◽  
Nripesh Prasad ◽  
Shawn E. Levy ◽  
Louis Stodieck ◽  
Angela Jones ◽  
...  

Author(s):  
Д.Д. Надыршина ◽  
А.В. Тюрин ◽  
Э.К. Хуснутдинова ◽  
Р.И. Хусаинова

Статья посвящена обсуждению подходов к классификации и обзору доступных литературных данных о клинической вариабельности и молекулярно-генетических основах патогенеза редкого наследственного заболевания - синдрома Элерса-Данло. Представленный обзор расширит представление о патогенезе и позволит оптимизировать диагностику данного синдрома, определить тактику лечения и медико-генетического консультирования отягощенных семей как клиническим генетикам, специалистам в области изучения орфанных заболеваний, так и врачам терапевтам, специалистам семейной медицины и общей врачебной практики. The article is devoted to the discussion of approaches to the classification and review of the available literature data on clinical variability and the molecular genetic basis of the pathogenesis of a rare hereditary disease - Ehlers-Danlos syndrome. The presented review will expand the understanding of the pathogenesis and allow to optimize the diagnosis of this syndrome, to determine the tactics of treatment and medical and genetic counseling of burdened families, both to clinical geneticists, specialists in the study of orphan diseases, and to general practitioners, specialists in family medicine and general medical practice.


Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 23
Author(s):  
Vera S. Bogdanova

Genetic analysis of nuclear-cytoplasm incompatibilities is not straightforward and requires an elaborated experimental design. A number of species have been genetically studied, but notable advances in genetic mapping of nuclear loci involved in nuclear-plastid incompatibility have been achieved only in wheat and pea. This review focuses on the study of the genetic background underlying nuclear-plastid incompatibilities, including cases where the molecular genetic basis of such incompatibility has been unveiled, such as in tobacco, Oenothera, pea, and wheat.


Author(s):  
Julie D. Scholes ◽  
Philip J. Swarbrick ◽  
Jon Slate ◽  
Malcolm C. Press

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