Genetic mechanism, baseline sensitivity and risk of resistance to oxathiapiprolin in oomycetes

Abstract Prefertilization mechanisms influencing selfing rates are thought to be absent in conifers. Outcrossing in conifers is promoted via an embryo-lethal system, but the genetic mechanism is poorly understood. This study is the first experimental profile of the genetic mechanism promoting outcrossing in conifers. Molecular dissection of a Pinus taeda L. selfed pedigree detected a chromosomal region identified as PtTX3020-RPtest9. Within this region, a semilethal factor was tightly linked (r = 0.0076) to a polymorphic expressed sequence tag (EST). The linkage group flanking the lethal factor showed strong heterozygote advantage. Using genotypic frequencies for the linkage group, three hypotheses about the semilethal factor could be tested: (1) the presence of a balanced lethal system, i.e., a lethal factor present in each of the two marker intervals; (2) gametic selection operative prior to fertilization; and (3) a stage-specific lethal factor. Selection acted via the embryo-lethal system. No support for a genetic mechanism operating prior to fertilization was found. The semilethal factor exerted no effect after embryo maturity. The genetic mechanism promoting outcrossing in P. taeda L. appears to have a balancing selection system due to either pseudo-overdominance or true overdominance.

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Human Handedness and Scalp Hair-Whorl Direction Develop From a Common Genetic Mechanism

Genetics ◽

10.1093/genetics/165.1.269 ◽

2003 ◽

Vol 165 (1) ◽

pp. 269-276

Author(s):

Amar J S Klar

Keyword(s):

Scalp Hair ◽

Single Gene ◽

Monozygotic Twins ◽

Hand Preference ◽

Genetic Mechanism ◽

Internal Organs ◽

Genetic Pathways ◽

Left Hand ◽

Learned Behavior ◽

Random Mixture

Abstract Theories concerning the cause of right- or left-hand preference in humans vary from purely learned behavior, to solely genetics, to a combination of the two mechanisms. The cause of handedness and its relation to the biologically specified scalp hair-whorl rotation is determined here. The general public, consisting of mostly right-handers (RH), shows counterclockwise whorl rotation infrequently in 8.4% of individuals. Interestingly, non-right-handers (NRH, i.e., left-handers and ambidextrous) display a random mixture of clockwise and counterclockwise swirling patterns. Confirming this finding, in another independent sample of individuals chosen because of their counterclockwise rotation, one-half of them are NRH. These findings of coupling in RH and uncoupling in NRH unequivocally establish that these traits develop from a common genetic mechanism. Another result concerning handedness of the progeny of discordant monozygotic twins suggests that lefties are one gene apart from righties. Together, these results suggest (1) that a single gene controls handedness, whorl orientation, and twin concordance and discordance and (2) that neuronal and visceral (internal organs) forms of bilateral asymmetry are coded by separate sets of genetic pathways. The sociological impact of the study is discussed.

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Integrative analysis of histomorphology, transcriptome and whole genome resequencing identified DIO2 gene as a crucial gene for the protuberant knob located on forehead in geese

BMC Genomics ◽

10.1186/s12864-021-07822-9 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Yan Deng ◽

Shenqiang Hu ◽

Chenglong Luo ◽

Qingyuan Ouyang ◽

Li Li ◽

...

Keyword(s):

Molecular Mechanisms ◽

Protein Secondary Structure ◽

Genomic Analysis ◽

Production Performance ◽

Genetic Mechanism ◽

Farm Animals ◽

Practical Significance ◽

Genome Resequencing ◽

Genomic Analyses ◽

Whole Genome Resequencing

Abstract Background During domestication, remarkable changes in behavior, morphology, physiology and production performance have taken place in farm animals. As one of the most economically important poultry, goose owns a unique appearance characteristic called knob, which is located at the base of the upper bill. However, neither the histomorphology nor the genetic mechanism of the knob phenotype has been revealed in geese. Results In the present study, integrated radiographic, histological, transcriptomic and genomic analyses revealed the histomorphological characteristics and genetic mechanism of goose knob. The knob skin was developed, and radiographic results demonstrated that the knob bone was obviously protuberant and pneumatized. Histologically, there were major differences in structures in both the knob skin and bone between geese owing knob (namely knob-geese) and those devoid of knob (namely non-knob geese). Through transcriptome analysis, 592 and 952 genes differentially expressed in knob skin and bone, and significantly enriched in PPAR and Calcium pathways in knob skin and bone, respectively, which revealed the molecular mechanisms of histomorphological differences of the knob between knob- and non-knob geese. Furthermore, integrated transcriptomic and genomic analysis contributed to the identification of 17 and 21 candidate genes associated with the knob formation in the skin and bone, respectively. Of them, DIO2 gene could play a pivotal role in determining the knob phenotype in geese. Because a non-synonymous mutation (c.642,923 G > A, P265L) changed DIO2 protein secondary structure in knob geese, and Sanger sequencing further showed that the AA genotype was identified in the population of knob geese, and was prevalent in a crossing population which was artificially selected for 10 generations. Conclusions This study was the first to uncover the knob histomorphological characteristics and genetic mechanism in geese, and DIO2 was identified as the crucial gene associated with the knob phenotype. These data not only expand and enrich our knowledge on the molecular mechanisms underlying the formation of head appendages in both mammalian and avian species, but also have important theoretical and practical significance for goose breeding.

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Possible Assortment of a1 and a2 Region Gene Segments in Human MHC Class I Molecules

Genetics ◽

10.1093/genetics/149.2.1063 ◽

1998 ◽

Vol 149 (2) ◽

pp. 1063-1067

Author(s):

George Johnson ◽

Tai T Wu

Keyword(s):

Nucleotide Sequence ◽

Mhc Class I ◽

Class I ◽

Genetic Mechanism ◽

Region Gene ◽

Exon 2 ◽

Similarities And Differences ◽

Pair Wise Comparison ◽

Sequence Similarities ◽

Mhc Class I Molecules

Abstract Using pair-wise comparison of aligned nucleotide sequences of distinct and complete human MHC class I molecules, we have constructed triangular tables to study the similarities and differences of various a1 (exon 2) and a2 (exon 3) region sequences. There are two HLA-A (A*6901 and A*6601) and 13 HLA-B (B*4201, B*8101, B*4102, B*4801, B*4007, B*4001, B*4802, Dw53, B*4406, B*4402, B*3901, B*1514 and B*3702) sequences that have identical a1 sequences with other known MHC class I molecules, while their a2 sequences are the same as those of different ones. Of these 15, A*6901, B*4001 and B*4802 have previously been suggested as the results of recombination between A*6801 and A*0201, B*4101 and B*8101, and B*4801 and B*3501, respectively. However, many other sequences can also be used to generate them by recombination. Furthermore, their reciprocal products have never been identified. Thus, gene conversion has subsequently been suggested as an alternative. Another possible genetic mechanism for generating these nucleotide sequence similarities can be assortment, or that some gene segments can be duplicated or multiplicated to be used in different human MHC class I molecules. Interestingly, this genetic mechanism is probably absent for the generation of different mouse MHC class I molecules.

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