Studies on female-sterility genes inDrosophila melanogaster

1956 ◽  
Vol 87 (3) ◽  
pp. 462-481 ◽  
Author(s):  
S. J. Counce
1977 ◽  
Vol 30 (2) ◽  
pp. 107-113 ◽  
Author(s):  
Takao K. Watanabe ◽  
Won Ho Lee

SUMMARYThe number of loci which are potentially able to produce sterility genes was estimated for Drosophila melanogaster. There appear to be, on the second chromosome, about 80 loci capable of producing male sterility and about 60 loci capable of producing female sterility. These figures seem to be considerably less than (400–500) loci responsible for lethal genes.


Genetics ◽  
1973 ◽  
Vol 74 (2) ◽  
pp. 351-361
Author(s):  
Chozo Oshima ◽  
Takao K Watanabe

ABSTRACT Three or four percent of the wild flies in natural populations of D. melanogaster have been found to be sterile. An analysis of sterility associated with the second chromosome revealed a much lower frequency of genetically sterile flies. The accumulation of sterility genes in a cage population was proportional to that of lethal genes, as were their equilibrium frequencies in several natural populations. Many sterile chromosomes were associated with low viability due to pleiotropic effects. The number of chromosomes leading to sterility in both sexes was larger than the expectation based on random combination of male and female sterility genes. This suggests that there is some linkage disequilibrium between male and female sterility genes, as well as a pleiotropic effect of single sterility genes. Some sterility genes were maintained in natural and cage populations, and the patterns of persistence of the sterility genes were very similar to those of lethal genes.


1943 ◽  
Vol 21c (2) ◽  
pp. 41-56 ◽  
Author(s):  
T. J. Arnason

Between 600 and 900 ovules are estimated to begin development in single normal potato ovaries. The number of seeds per fruit ranged from 0 to 183 in 1941, from 7 to 472 in 1942.Sectioned ovules from several potato varieties were examined. Estimates of the proportion of aborted ovules from freshly opened flowers or nearly mature buds were as follows: Minn. 75-5: 10%, Earlaine: 15%, Early Ohio: 20%, Irish Cobbler: 30–40%, Sebago: 60%, U.S.D.A. 46000: 80%, Netted Gem: 100%. Pollen from the first two varieties only in this list has been used successfully in crosses. In Netted Gem few gametophytes began development, most of the abortion occurring earlier. In the other varieties a larger proportion of the abortion became evident after gametophyte development had been initiated. In Sebago many embryo sacs were immature in freshly opened flowers. Inexact distribution of chromosomes at meiosis probably accounts for a part of the observed abortion. Sterility genes may be responsible for a part. Premature bud and flower abscission lowers the expressed fertility of all varieties but is more effective in some: e.g. Netted Gem and Early Ohio, than in others, e.g. Minn. 75-5 and Earlaine. Fertilization in Irish Cobbler occurred mainly two to four days after pollination; 50% of ovules in the upper half of the ovary showed endosperm divisions. Evidence of fertilization was seen in less than 5% of ovules of U.S.D.A. 46000 taken four days after pollination. Nutritive cells of the integument became considerably enlarged in many ovules containing aborted embryo sacs.


Genome ◽  
2015 ◽  
Vol 58 (4) ◽  
pp. 143-149 ◽  
Author(s):  
Benjamin Speth ◽  
Joshua P. Rogers ◽  
Napatsakorn Boonyoo ◽  
A.J. VanMeter ◽  
Jordan Baumbach ◽  
...  

In soybean, asynaptic and desynaptic mutants lead to abnormal meiosis and fertility reduction. Several male-sterile, female-sterile mutants have been identified and studied in soybean, however, some of these mutants have not been mapped to locations on soybean chromosomes. The objectives of this study were to molecularly map five male-sterile, female-sterile genes (st2, st4, st5, st6, and st7) in soybean and compare the map locations of these genes with already mapped sterility genes. Microsatellite markers were used in bulked segregant analyses to locate all five male-sterile, female-sterile genes to soybean chromosomes, and markers from the corresponding chromosomes were used on F2 populations to generate genetic linkage maps. The st2, st4, st5, st6, and st7 genes were located on molecular linkage group (MLG) B1 (chromosome 11), MLG D1a (chromosome 01), MLG F (chromosome 13), MLG B2 (chromosome 14), and D1b (chromosome 02), respectively. The st2, st4, st5, st6, and st7 genes were flanked to 10.3 (∼399 kb), 6.3 (∼164 kb), 3.9 (∼11.8 Mb), 11.0 (∼409 kb), and 5.3 cM (∼224 kb), and the flanked regions contained 57, 17, 362, 52, and 17 predicted genes, respectively. Future characterization of candidate genes should facilitate identification of the male- and female-fertility genes, which may provide vital insights on structure and function of genes involved in the reproductive pathway in soybean.


1977 ◽  
Vol 19 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Jirair Carapetian ◽  
Earlene A. Rupert

Microsporogenesis was studied in the male-female sterile F2 segregants of a safflower cross involving 'US-10' and '57-147' cuitivars and was compared with normal meiosis in the F1 hybrids. In the microspores of the sterile plants contraction of chromosomes during prophase was irregular and patchy and they did not stain well with acetocarmine. At MI, most of the 24 chromosomes tended to stick to each other at random resulting in the formation of several chromosome bridges during AI. Multipolar meiotic divisions were observed. The second division was rarely seen. Apparently, meiosis ends with a multipolar AI separation and with the formation of 3- to 9-celled "quartets" which later develop nonfunctional pollen grains. The onset of meiosis in sterile plants was delayed and microsporogenesis subsequently progressed at a much slower rate than in fertile F1 hybrids. Three interacting nuclear genes appear to cause male-female sterility and affect microsporogenesis by interfering with some component essential for normal meiosis.


Development ◽  
1957 ◽  
Vol 5 (4) ◽  
pp. 404-421
Author(s):  
S. J. Counce ◽  
D. A. Ede

Waddington (1956) has called attention to the importance of the relation between the structure of the egg and hereditary factors which determine characters in the developing organism: ‘When we discuss the eggs of the different kinds of animals, we…find that the eventual origin from which the whole later development springs is the orderly arrangement of essential parts of the ovum. We must therefore enquire a little more deeply how this arrangement is brought about. In particular, what is the relation between it and the hereditary factors or genes which determine the detailed character of the adult organism?’ Although, in most animals, no such relations have been carefully studied (with the exception of direction of coiling in Limnea) there exists in Drosophila a class of female-sterility genes or factors in which females are sterile because the egg cytoplasm will not support the development of a viable zygote (Lynch, 1919; Merrell, 1947; Counce, 1956 a, b, c); e.g. when a female heterozygous for the gene is mated to a mutant male, females homozygous for the factor develop into adults; however, when these homozygous mutant females are mated, their offspring never develop to an adult stage.


1994 ◽  
Vol 42 (3) ◽  
pp. 325 ◽  
Author(s):  
J Carapetian

Three interacting, unlinked, nuclear genes are reported to control the inheritance of male-female sterility in safflower (Carthamus tinctorius L.). In a cross between US-10 cultivar (genotype S(1)S(1)s(2)s(2)s(3)s(3)) and a geographically distant Indian line 57-147 (genotype s(1)s(1)S(2)S(2)S(3)S(3)), F-2 plants segregated 57 fertile:7 sterile. Sterile genotypes set no seed under natural conditions. This study reports the effects of sterility genes on the inflorescence and pollen grains. Floret elongation was limited in sterile plants at bloom. Lengths of florets in the sterile individuals showed a 17% and a 40% reduction one day before and on the day of anthesis, respectively. This resulted in a conspicuous pinched appearance of the capitula. Lack of seed development in sterile plants hindered the expansion of capitula and prevented the dried florets from lying against the imbricate bracts as in normal fertile plants. The percentage pollen stainability was 96.1 in US-10, 87.5 in 57-147, 91.3 in the F-1, 90.5 in fertile F-2, and 1.4 in sterile F-2 plants. However, none of the stainable pollen grains of the sterile F-2 plants was viable. The mean pollen diameter was 53.2 in US-10, 56.3 in 57-147, 53.9 in the F-1, 58.1 in fertile F-2, and 35.8 mu m in sterile F-2 plants. Sterile plants exhibited a greater variation in pollen diameter than the fertile plants. Light and scanning electron microscopy observations revealed the absence of normally sculptured and tricolpate pollen from the sterile plants. The results suggest that the sterility genes have their effects primarily on reproductive organs, but do not hinder vegetative development and growth of sterile plants before they bloom.


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