Dominant and Recessive Effects of Electrophoretically Detected Specific Locus Mutations

Author(s):  
Susan E. Lewis ◽  
Franklin M. Johnson
Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 787-799
Author(s):  
Brad A Rikke ◽  
Dabney K Johnson ◽  
Thomas E Johnson

The murine albino-deletion complex developed as part of the Oak Ridge specific-locus test covers 6–11 cM of chromosome 7. This complex has proven to be a valuable resource for localizing traits to a small target region suitable for positional cloning. In this study, we mapped the endpoints of deletions in this complex using all of the available Mit simple-sequence length polymorphism (SSLP) markers. Concurrently, this mapping has determined the map order of nearly all of the SSLP markers, most of which were previously unresolved. The SSLP-based deletion map was confirmed and genetic distances were determined using the European Collaborative Interspecific Backcross panel of nearly a thousand mice. The average SSLP marker resolution is 0.3–0.4 cM, comparable to the cloning capacity of yeast artificial chromosomes (YACs). The SSLP markers were then used to construct a genetically anchored YAC framework map that further confirms the deletion map. We find that the largest deleted region distal to Tyr is about two to three times larger than the largest proximal deleted region, and the original C3H/101 regions flanking the deletions (moved to an St2A cch/cch background) are smaller than anticipated, which we suggest may result from increased recombination rates immediately flanking the deleted regions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sonia Moreno-Grau ◽  
◽  
Maria Victoria Fernández ◽  
Itziar de Rojas ◽  
Pablo Garcia-González ◽  
...  

AbstractLong runs of homozygosity (ROH) are contiguous stretches of homozygous genotypes, which are a footprint of inbreeding and recessive inheritance. The presence of recessive loci is suggested for Alzheimer’s disease (AD); however, their search has been poorly assessed to date. To investigate homozygosity in AD, here we performed a fine-scale ROH analysis using 10 independent cohorts of European ancestry (11,919 AD cases and 9181 controls.) We detected an increase of homozygosity in AD cases compared to controls [βAVROH (CI 95%) = 0.070 (0.037–0.104); P = 3.91 × 10−5; βFROH (CI95%) = 0.043 (0.009–0.076); P = 0.013]. ROHs increasing the risk of AD (OR > 1) were significantly overrepresented compared to ROHs increasing protection (p < 2.20 × 10−16). A significant ROH association with AD risk was detected upstream the HS3ST1 locus (chr4:11,189,482‒11,305,456), (β (CI 95%) = 1.09 (0.48 ‒ 1.48), p value = 9.03 × 10−4), previously related to AD. Next, to search for recessive candidate variants in ROHs, we constructed a homozygosity map of inbred AD cases extracted from an outbred population and explored ROH regions in whole-exome sequencing data (N = 1449). We detected a candidate marker, rs117458494, mapped in the SPON1 locus, which has been previously associated with amyloid metabolism. Here, we provide a research framework to look for recessive variants in AD using outbred populations. Our results showed that AD cases have enriched homozygosity, suggesting that recessive effects may explain a proportion of AD heritability.


1957 ◽  
Vol 103 (433) ◽  
pp. 758-772 ◽  
Author(s):  
Victor Meyer ◽  
H. Gwynne Jones

Various investigations into the effects of brain injury on psychological test performance (Weisenburg and McBride, 1935; Patterson and Zangwill, 1944; Anderson, 1951; McFie and Piercy, 1952; Bauer and Becka, 1954; Milner, 1954) suggest the overall conclusion that patients with left hemisphere lesions are relatively poor at verbal tasks, while those with right-sided lesions do worst at practical tasks, particularly the manipulation of spatial or spatio-temporal relationships. Heilbfun's (1956) study confirmed that verbal deficits result from left-sided lesions but his left and right hemisphere groups produced almost identical scores on spatial tests. In so far as these workers paid attention to the specific sites of the lesions, their findings indicate that the pattern of test performance is a function of the hemisphere in which the lesion occurs rather than of its specific locus.


1979 ◽  
Vol 76 (11) ◽  
pp. 5818-5819 ◽  
Author(s):  
W. L. Russell ◽  
E. M. Kelly ◽  
P. R. Hunsicker ◽  
J. W. Bangham ◽  
S. C. Maddux ◽  
...  
Keyword(s):  

Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 769-777
Author(s):  
Michael A Cantrell ◽  
Brian J Filanoski ◽  
Angela R Ingermann ◽  
Katherine Olsson ◽  
Nicole DiLuglio ◽  
...  

Abstract Vertebrate retrotransposons have been used extensively for phylogenetic analyses and studies of molecular evolution. Information can be obtained from specific inserts either by comparing sequence differences that have accumulated over time in orthologous copies of that insert or by determining the presence or absence of that specific element at a particular site. The presence of specific copies has been deemed to be an essentially homoplasy-free phylogenetic character because the probability of multiple independent insertions into any one site has been believed to be nil. Mys elements are a type of LTR-containing retrotransposon present in Sigmodontine rodents. In this study we have shown that one particular insert, mys-9, is an extremely old insert present in multiple species of the genus Peromyscus. We have found that different copies of this insert show a surprising range of sizes, due primarily to a continuing series of SINE (short interspersed element) insertions into this locus. We have identified two hot spots for SINE insertion within mys-9 and at each hot spot have found that two independent SINE insertions have occurred at identical sites. These results have major repercussions for phylogenetic analyses based on SINE insertions, indicating the need for caution when one concludes that the existence of a SINE at a specific locus in multiple individuals is indicative of common ancestry. Although independent insertions at the same locus may be rare, SINE insertions are not homoplasy-free phylogenetic markers.


Author(s):  
М. А. Dolzhikova ◽  
А. А. Pavlenko ◽  
А. V. Pikunova ◽  
O. D. Golyaeva

In the presented studies the genotypes of 46 varieties of red currant (Ribes rubrum) from the All-Russian Research Institute of Fruit Crops Breeding (VNIISPK) the collection were studied for 14 microsatellite locus. The data were obtained by the detection method of – fragment analysis using capillary electrophoresis. Varieties with rare, unique alleles and combinations of alleles have been identified. In most cases, no more than two fragments were identified for each genotype for a specific locus, but three fragments at some loci were amplified in the samples (Orlovchanka, Konstantinovskaya, Nadezhda – e3-B02; Marmeladnitsa – g2-G12; Nadezhda – g2-J08; Svetlitsa, Tatianina – g1-L12). The profiles of the cultivars Cascad and Red cross are identical to each other, although they differ from the others. The Red cross [(Cherry × White Grape] and Cascad [(free pollination of the variety Diploma (Cherry × White grape)]] varieties were developed in the USA and have common ancestors. It can be assumed the collection under different names contains the same genotype or that these pairs of varieties are so similar that the polymorphism of the analyzed loci is not enough to distinguish them. To prevent a shift in the size of alleles control varieties were selected and proposed, zoned in the territory of the Russian Federation – Gazelle (originator of VNIISPK: Chulkovskaya × Maarses Prominent) and Valentinovka (originator of VNIISPK: Rote Shpetlese × Jonker van Tets). The data obtained on the polymorphism microsatellite loci Red currant can be used for further identification.


Nature ◽  
1976 ◽  
Vol 264 (5588) ◽  
pp. 715-719 ◽  
Author(s):  
Seymour Abrahamson ◽  
Sheldon Wolff

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