Showing papers in "Journal of Heredity in 1983"

Linkage map of Arabidopsis thaliana

Abstract: For Arabidopsis thaliana (L.) Heynh. (2n = 10), 76 loci have now been assigned to five linkage groups, corresponding to the five chromosomes. From a large number of estimated recombination percentages Internally consistent linkage maps were con- structed, ranging in genetic length from 51 cM (chromosome 2) to 123 cM (chromosome 1). Map lengths and centromere positions agree well with cytological observations of pre-

Hereditary progressive retinal atrophy in the Abyssinian cat

Abstract: Progressive retinal atrophy (PRA), a hereditary eye disease leading to blindness, was found in the Abyssinian breed of cat. Sixty-eight cases of a bilateral generalized retinopathy, at different stages of the disease process, were seen in the breed during ophthalmoscopic examinations of cats throughout Sweden during a 2-year period. Forty-five percent of cats aged 2 years or older were affected in the examined group. The earliest case was diagnosed in a 16-month-old cat. At the age of 3-4 years a bilateral retinal atrophy was usually present in affected cats. Genetic analysis indicates that PRA in the Abyssinian cat is caused by an autosomal recessive gene.

Toxic milk, a new mutation affecting copper metabolism in the mouse

Abstract: Toxic milk, tx, a new autosomal recessive mutation in mice is described. Litters produced by mutant females display a syndrome including poor growth, hypopigmentation, tremors, and ultimately death at two weeks of age. These features, consistent with copper deficiency, are attributed to failure in gestational hepatic copper accumulation exacerbated by subsistence on milk with greatly reduced copper content. Such infants can be rescued by foster-nursing on normal dams or by administered of supplemental cooper. Mutants themselves amass extraordinarily large concentrations of hepatic copper that ultimately leads to liver disease. Erroneous hepatic copper metabolism is further evidenced by reduced ceruloplasmin activity.

Frequency of spontaneous and induced “point” mutations in higher eukaryotes

Abstract: Data are presented on comparative mutation rates in Drosophila, mice, and humans, as derived from the study of both biochemical and morphological traits. There is a notable similarity in these rates, despite the large differences in average generation time, mean body temperature, and number of cell divisions intervening between fertilization of the egg and production of functional gametes. This suggests the evolution of superior genetic (DNA) repair strategies in (long-lived) humans. Evidence is reviewed that raises the possibility of higher mutation rates in mostly tropical-dwelling, tribal human populations than in temperate-dwelling civilized groups. The data suggesting that humans may be somewhat less sensitive to the genetic effects of radiation than mice are presented, and the question of whether this apparent difference is real or spurious is discussed. Finally, some possible new directions in the study of the mutation-selection balance are presented.

Population structure and Mdh- 1 locus variation in Apis mellifera ligustica

Abstract: In a wide area of the Piedmont of Italy the apiaries of Apis mellifera ligustica Spin., (the Italian bee) show homogeneous allelic frequency distributions at the Mdh-1 locus, the only one known to be polymorphic in worker bees. This can be explained by considering that an apiary is not a closed genetic system and that among apiaries gene flow is sufficient to overcome the different forces of inbreeding and random genetic drift. Nevertheless there is some evidence for partial subdivision because the pooled samples show a weak Wahlund effect. Moreover, the M allele at the same locus can be used as a diagnostic marker to distinguish A. m. ligustica populations (M absent or at very low frequencies) from A. m. mellifera French populations (monomorphic for M). The two honey-bee varieties, almost entirely separated by the Alps, hybridize with each other in very limited alpine areas. Hybrid populations show intermediate M frequencies.

Dilute suppressor, a new suppressor gene in the house mouse

Abstract: Dilute suppressor, dsu, a new fully penetrant autosomal recessive mutation, acts by restoring melanocytes of homozygous dilute (d/d) mice to normal shape and almost normal number This action creates a nondilute appearing coat color in dilute mice Dilute suppressor is located on chromosome 1 linked to isocitrate dehydrogenase (Idh-I) with 625 +/- 349 percent recombination, and is not linked to dilute, which is on chromosome 9

Genetic differences in pupal diapause incidence between two selected strains of the flesh fly

Abstract: This study assesses the importance of genetic differences that underlie differences in pupal diapause incidence among two lines of the flesh fly, Sarcophaga bullata. Lines of high and low diapause Incidence were derived through selection and subsequent Inbreeding from an original strain and the diapause incidence was observed among F1, F2, and backcross progeny in a strongly diapause-inducing environment. Results consistently revealed patterns indicating that diapause capability is greatly dependent on heritable factors, although the patterns of Inheritance are not additive. The observed differences in diapause levels resulting from artificial selection imply that local natural populations exhibit a large amount of variability in response to diapause-inducing environmental factors. A relatively small number of gene loci are likely to control the diapause response in this species.

Histocompatibility bioassays of population structure in marine sponges Clonal structure in Verongia longissima and lotrochota birotulata

Abstract: Author(s): Neigel, JE; Avise, JC | Abstract: Clonal population structure in two marine sponges, Verongia longissimia and lotrochota birotulata, was examined with a self-recognition bioassay. The bioassay consists of grafts of branch segments between conspecific individuals. Results were consistent with the operational properties expected of a precise histocompatibility system. Autografts exhibited acceptance responses; grafts between individuals separated by large distances exhibited rejection responses; Individuals were not limited to a single mode of response at one time; and all identity relationships were transitive. Clonal population structure was assessed by examining the relationship between graft response and donor-to-recipient distance, and by actually mapping the distributions of particular clones. Clones of lotrochota birotulata were usually restricted to single coral heads or small patch reefs (1-3 m diameter). For Verongla longissima, which can grow directly upon the coral rubble surrounding coral heads and patch reefs, individual clones often occupied larger areas (up to 10 m diameter). The spatial patterns of clonal distributions are readily interpreted as consequences of the particular demographies and habitat specificitles of these two species. / 1983, American Genetic Association.

Blind-sterile: a new mutation on chromosome 2 of the house mouse

Abstract: The inheritance and developmental effects of a new recessive mutation in the mouse, blind-sterile (bs), are described. This mutation causes lenticular cataracts and glossy coat in males and females and sterility in males due to arrested spermatogenesis. Blind-sterile is located on chromosome 2, near agouti.

Apomictic and sexual pearl millet X Pennisetum squamulatum hybrids

Abstract: Pennisetum squamulatum Fresen, an apomictic East African grass (2n = 54) was crossed to tetraploid (2n = 28) sexual pearl millet, P. americanum L. Leeke to study the potential for germplasm exchange. Twenty interspecific hybrids (2n = 41) with 14 pearl millet and 27 P. squamulatum chromosomes were obtained. All resembled P. squamulatum in perennial growth habit and inflorescence characteristics and resembled pearl millet in leafiness and pencillate anther tips. Seventeen of these hybrids were more vigorous than either parent. The most common chromosome association at metaphase I was 18 bivalents plus 5 univalents. At anaphase I and telophase I laggards, fragments, and unequal chromosome distribution were observed. Fifteen of 17 interspecific hybrids reproduced by facultative apomixis, one was sexual and one was an obligate apomict. Ovules with aposporous embryo sacs ranged from 1 to 93% in facultative apomictic plants. Morphological characteristics and chromosome numbers of open-pollinated progeny from the apomictic interspecific hybrid were identical to those of the seed parent indicating obligate apomictic reproduction. Both sexual and apomictic hybrids were partially male fertile with pollen stainability ranging from 29 percent to 79 percent and seed-set ranging from 1 to 60 seed per inflorescence under open-pollination. Development of fertile apomictic more » pearl millet-P. squamulatum interspecific hybrids appears to be a very useful tool for the transfer of genes for apomixis from the wild species to pearl millet. « less

Hyperspiny Purkinje cell, a new neurological mutation in the mouse

Abstract: Hyperspiny Purkinje cell (hpc) is a new autosomal recessive mutation of the laboratory mouse. Homozygotes exhibit abnormal motor behavior, with predominance of cerebellar symptoms, about 10 days after birth. Morphological analysis disclosed a slightly reduced cerebellum with selective alteration of Purkinje cells. All these neurons have an atrophic dendritic tree. The proximal dendritic branches and the cell bodies, instead of being smooth, are studded with spines. Most of the axon terminals belonging to this neuronal population undergo progressive degenerative changes. Cell death is observed in only a small proportion of Purkinje cells. Electrophysiological study revealed that the synapses between climbing fibers and Purkinje cells are functional with no gross abnormality.

Shaker short-tail, a spontaneous neurological mutant in the mouse

Abstract: A spontaneous mutation that occurred in the Inbred strain BALB/cCF In 1980 proved to be inherited as a single autosomal recessive gene with complete penetrance. Homozygous recessive animals have a short or blunt tall, an irregular pattern of foliation of the cerebellum, delayed development of the righting reflex, and a wide variety of other peculiar behaviors. The effects of this mutation strongly resemble those of the shaker-short (st) gene reported by Dunn in 1934 that is now extinct. The gene designation, sst, is proposed for the new shaker short-tall mutation.

Segregation and mapping of allozymes of the apple maggot fly

Abstract: The genetics of electrophoretic enzyme variants (allozymes) of 11 enzymes of the apple maggot, Rhagoletis pomonella, has been investigated by single-pair crosses. All allozymes segregated as simple Mendelian genes. Null alleles occur at two enzymes--phosphoglucomutase and alcohol dehydrogenase. Five linkage groups have been established.