Genetic characterization of ms (3) K81, a paternal effect gene of Drosophila melanogaster.

Genetics ◽  
1995 ◽  
Vol 140 (1) ◽  
pp. 219-229 ◽  
Author(s):  
G K Yasuda ◽  
G Schubiger ◽  
B T Wakimoto
Keyword(s):  
Drosophila Melanogaster ◽  
Developmental Stages ◽  
Normal Function ◽  
Loss Of Function ◽  
Male Sterile ◽  
Specific Product ◽  
Paternal Effect ◽  
Developmental Arrest ◽  
Effect Gene

Abstract The vast majority of known male sterile mutants of Drosophila melanogaster fail to produce mature sperm or mate properly. The ms(3) K81(1) mutation is one of a rare class of male sterile mutations in which sterility is caused by developmental arrest after sperm entry into the egg. Previous studies showed that males homozygous for the K81(1) mutation produce progeny that arrest at either of two developmental stages. Most embryos arrest during early nuclear cycles, whereas the remainder are haploid embryos that arrest at a later stage. This description of the mutant phenotype was based on the analysis of a single allele isolated from a natural population. It was therefore unclear whether this unique paternal effect phenotype reflected the normal function of the gene. The genetic analysis and initial molecular characterization of five new K81 mutations are described here. Hemizygous conditions and heteroallelic combinations of the alleles were associated with male sterility caused by defects in embryogenesis. No other mutant phenotypes were observed. Thus, the K81 gene acted as a strict paternal effect gene. Moreover, the biphasic pattern of developmental arrest was common to all the alleles. These findings strongly suggested that the unusual embryonic phenotype caused by all five new alleles was due to loss of function of the K81+ gene. The K81 gene is therefore the first clear example of a strict paternal effect gene in Drosophila. Based on the embryonic lethal phenotypes, we suggest that the K81+ gene encodes a sperm-specific product that is essential for the male pronucleus to participate in the first few embryonic nuclear divisions.

scholarly journals Genetic and Molecular Characterization of sting, a Gene Involved in Crystal Formation and Meiotic Drive in the Male Germ Line of Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 749-760 ◽  
Author(s):  
Armin Schmidt ◽  
Gioacchino Palumbo ◽  
Maria P Bozzetti ◽  
Patrizia Tritto ◽  
Sergio Pimpinelli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Drosophila Melanogaster ◽  
Null Allele ◽  
Germ Line ◽  
Meiotic Drive ◽  
P Element ◽  
Crystal Formation ◽  
Male Sterile ◽  
Male Sterile Mutation

Abstract The sting mutation, caused by a P element inserted into polytene region 32D, was isolated by a screen for male sterile insertions in Drosophila melanogaster. This sterility is correlated with the presence of crystals in spermatocytes and spermatids that are structurally indistinguishable from those produced in males carrying a deficiency of the Y-linked crystal (cry) locus. In addition, their morphology is needle-like in Ste+ flies and star-shaped in Ste flies, once again as observed in cry– males. The sti mutation leads to meiotic drive of the sex chromosomes, and the strength of the phenomenon is correlated with the copy number of the repetitive Ste locus. The same correlation is also true for the penetrance of the male sterile mutation. A presumptive sti null allele results in male sterility and lethal maternal effect. The gene was cloned and shown to code for a putative protein that is 866 amino acids long. A C-terminal domain of 82 amino acids is identified that is well conserved in proteins from different organisms. The gene is expressed only in the germline of both sexes. The interaction of sting with the Ste locus can also be demonstrated at the molecular level. While an unprocessed 8-kb Ste primary transcript is expressed in wild-type males, in X/Y homozygous sti males, as in X/Y cry– males, a 0.7-kb mRNA is produced.

scholarly journals Cytoplasmic dynein (ddlc1) mutations cause morphogenetic defects and apoptotic cell death in Drosophila melanogaster.

1996 ◽  
Vol 16 (5) ◽  
pp. 1966-1977 ◽  
Author(s):  
T Dick ◽  
K Ray ◽  
H K Salz ◽  
W Chia
Keyword(s):  
Drosophila Melanogaster ◽  
Light Chain ◽  
Blot Analysis ◽  
Cytoplasmic Dynein ◽  
P Element ◽  
Female Sterility ◽  
Dynein Light Chain ◽  
Loss Of Function ◽  
Light Chain Gene

We report the molecular and genetic characterization of the cytoplasmic dynein light-chain gene, ddlc1, from Drosophila melanogaster. ddlc1 encodes the first cytoplasmic dynein light chain identified, and its genetic analysis represents the first in vivo characterization of cytoplasmic dynein function in higher eucaryotes. The ddlc1 gene maps to 4E1-2 and encodes an 89-amino-acid polypeptide with a high similarity to the axonemal 8-kDa outer-arm dynein light chain from Chlamydomonas flagella. Developmental Northern (RNA) blot analysis and ovary and embryo RNA in situ hybridizations indicate that the ddlc1 gene is expressed ubiquitously. Anti-DDLC1 antibody analyses show that the DDLC1 protein is localized in the cytoplasm. P-element-induced partial-loss-of-function mutations cause pleiotropic morphogenetic defects in bristle and wing development, as well as in oogenesis, and hence result in female sterility. The morphological abnormalities found in the ovaries are always associated with a loss of cellular shape and structure, as visualized by a disorganization of the actin cytoskeleton. Total-loss-of-function mutations cause lethality. A large proportion of mutant animals degenerate during embryogenesis, and the dying cells show morphological changes characteristic of apoptosis, namely, cell and nuclear condensation and fragmentation, as well as DNA degradation. Cloning of the human homolog of the ddlc1 gene, hdlc1, demonstrates that the dynein light-chain 1 is highly conserved in flies and humans. Northern blot analysis and epitope tagging show that the hdlc1 gene is ubiquitously expressed and that the human dynein light chain 1 is localized in the cytoplasm. hdlc1 maps to 14q24.

scholarly journals Characterization of Suppressor of fused, a complete suppressor of the fused segment polarity gene of Drosophila melanogaster.

Genetics ◽  
1992 ◽  
Vol 132 (3) ◽  
pp. 725-736 ◽  
Author(s):  
T Préat
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effect ◽  
Opposite Effect ◽  
Loss Of Function ◽  
Suppressor Of Fused ◽  
Segment Polarity ◽  
New Gene ◽  
Segment Polarity Gene ◽  
Polarity Gene

Abstract fused (fu) is a maternal effect segment polarity gene of Drosophila melanogaster. In addition, fu females have tumorous ovaries. Two ethyl methanesulfonate mutageneses were carried out in order to isolate suppressors of the fu phenotype. A new gene, Suppressor of fused (Su(fu)), was identified. It is located in the 87C8 region of the third chromosome. Su(fu) displays a maternal effect and is also expressed later in development. Although Su(fu)LP is a complete loss-of-function mutation, it is homozygous viable and has no phenotype by itself. Su(fu) fully suppresses the embryonic and adult phenotypes of fu mutants. Su(fu) mutations are semidominant and a Su(fu)+ duplication has an opposite effect, enhancing the fused phenotype. It is proposed therefore that the Su(fu)+ product is involved in the same developmental step as the Fu+ kinase. Thus, a new gene interacting with the segment polarity pathway was identified using an indirect approach.

scholarly journals The exuperantia gene is required for Drosophila spermatogenesis as well as anteroposterior polarity of the developing oocyte, and encodes overlapping sex-specific transcripts.

Genetics ◽  
1990 ◽  
Vol 126 (3) ◽  
pp. 607-617 ◽  
Author(s):  
T Hazelrigg ◽  
W S Watkins ◽  
D Marcey ◽  
C Tu ◽  
M Karow ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Vital Function ◽  
Male Sterile ◽  
Maternal Effect Gene ◽  
Gene Functions ◽  
Sterile Mutant ◽  
Female Germline ◽  
Anteroposterior Polarity ◽  
Effect Gene

Abstract The Drosophila gene exuperantia (exu) is a maternal effect gene which is needed for proper localization of the bcd RNA during the formation of oocytes. We have extended the characterization of the exu phenotype and find that the gene functions in the male as well as the female germline. Six of seven exu alleles are male-sterile; mutant defects in spermatogenesis first appear during meiosis. A genetic analysis presented here shows that the exu gene does not encode a zygotic vital function. The isolation of two overlapping deficiencies that delete exu function localizes the gene cytologically to polytene bands 57A4-B1. We describe the molecular cloning and identification of the gene, and show that it encodes overlapping sex-specific transcripts of 2.9 kb in the male and 2.1 kb in the female. We also show that these two transcripts are limited in expression to the germline. We demonstrate that one allele, exuVL57, is a deletion of about 700 bp which results in a loss of both transcripts.

scholarly journals Relationship between chromosome content and nuclear diameter in early spermatids of Drosophila melanogaster

1989 ◽  
Vol 54 (3) ◽  
pp. 205-212 ◽  
Author(s):  
Cayetano González ◽  
José Casal ◽  
Pedro Ripoll
Keyword(s):  
Drosophila Melanogaster ◽  
Light Microscopy ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Wild Type ◽  
Male Sterile ◽  
Nuclear Diameter ◽  
Early Spermatid ◽  
The Relationship

SummaryWe have studied, using light microscopy, the relationship between chromosome content and nuclear diameter in early spermatids of males carrying different combinations of wild-type and compound chromosomes in Drosophila melanogaster. By using these genotypes we have been able to observe spermatid nuclei bearing various numbers of chromosomes ranging from only one sex chromosome and no major autosomes to almost twice the normal chromosome complement. We have found that variations in the chromosome content are accompanied by increasing the variance in early spermatid nuclear diameter; the more gametic classes produced, the higher the variance of nuclear diameters. These results indicate that measuring nuclear diameters in early spermatids represents a useful way to estimate the levels of meiotic non-disjunction and thereby to improve the characterization of lethal or male sterile mutants in which analysis of meiotic chrosome non-disjunction cannot be achieved by conventional genetic methods.

scholarly journals Two types of genetic interaction implicate the whirligig gene of Drosophila melanogaster in microtubule organization in the flagellar axoneme.

Genetics ◽  
1990 ◽  
Vol 126 (4) ◽  
pp. 961-973 ◽  
Author(s):  
L L Green ◽  
N Wolf ◽  
K L McDonald ◽  
M T Fuller
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Interaction ◽  
Dominant Male ◽  
Loss Of Function ◽  
Male Sterile ◽  
Microtubule Organization ◽  
Beta Tubulin ◽  
Absolute Level ◽  
Alpha Tubulin ◽  
Flagellar Axoneme

Abstract The mutant nc4 allele of whirligig (3-54.4) of Drosophila melanogaster fails to complement mutations in an alpha-tubulin locus, alpha 1t, mutations in a beta-tubulin locus, B2t, or a mutation in the haywire locus. However, wrl fails to map to any of the known alpha- or beta-tubulin genes. The extragenic failure to complement could indicate that the wrl product participates in structural interactions with microtubule proteins. The whirligig locus appears to be haploinsufficient for male fertility. Both a deficiency of wrl and possible loss of function alleles obtained by reverting the failure to complement between wrlnc4 and B2tn are dominant male sterile in a genetic background wild type for tubulin. The dominant male sterility of the revertant alleles is suppressed if the flies are also heterozygous for B2tn, for a deficiency of alpha 1t, or for the haync2 allele. These results suggest that it is not the absolute level of wrl gene product but its level relative to tubulin or microtubule function that is important for normal spermatogenesis. The phenotype of homozygous wrl mutants suggests that the whirligig product plays a role in postmeiotic spermatid differentiation, possibly in organizing the microtubules of the sperm flagellar axoneme. Flies homozygous for either wrlnc4 or revertant alleles are viable and female fertile but male sterile. Premeiotic and meiotic stages of spermatogenesis appear normal. However, in post-meiotic stages, flagellar axonemes show loss of the accessory microtubule on the B-subfiber of outer doublet microtubules, outer triplet instead of outer doublet microtubules, and missing central pair microtubules.

scholarly journals Characterization of the Male-sterile Line Bcajh97-01A/B and Identification of Candidate Genes for Genic Male Sterility in Chinese Cabbage-pak-choi

2009 ◽  
Vol 134 (6) ◽  
pp. 632-640 ◽  
Author(s):  
Li Huang ◽  
Wan-zhi Ye ◽  
Ting-ting Liu ◽  
Jia-shu Cao
Keyword(s):  
Male Sterility ◽  
Candidate Genes ◽  
Chinese Cabbage ◽  
Developmental Stages ◽  
Male Sterile ◽  
Male Sterile Line ◽  
Flower Buds ◽  
Pak Choi ◽  
Genic Male Sterility

Cytological features of ‘Aijiaohuang’ chinese cabbage-pak-choi (Brassica campestris ssp. chinensis) Bcajh97-01A/B genic male-sterile AB line were examined to determine phenotypic reasons for male sterility. The sterile line Bcajh97-01A was found to undergo aberrant cytokinesis during male meiosis. Transcriptional profiling of the flower buds of both fertile and sterile plants was performed at the periods preceding meiosis, at the tetrad to uninucleate pollen period, and at the binucleate to mature pollen period. Transcript-derived fragments (TDFs) from corresponding genes that were expressed in flower buds at these three different stages could be divided into nine classes. We sequenced a total of 14 new TDFs that were differentially displayed at particular pollen developmental stages, including eight genes with unknown or hypothetical functions and six genes showing significant homology with known genes. This characterization of the Bcajh97-01A genic male-sterile line allowed the identification of candidate genes underlying genic male sterility.

Identification and characterization of Caenorhabditis elegans gamma-tubulin in dividing cells and differentiated tissues

2000 ◽  
Vol 113 (21) ◽  
pp. 3747-3759 ◽  
Author(s):  
Y. Bobinnec ◽  
M. Fukuda ◽  
E. Nishida
Keyword(s):  
Caenorhabditis Elegans ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Loss Of Function ◽  
Tubulin Gene ◽  
Gfp Reporter ◽  
Dividing Cells ◽  
Gamma Tubulin ◽  
Identification And Characterization

gamma-Tubulin is an essential component of the microtubule-nucleation machinery and therefore plays a crucial role during mitosis. To gain further insights into the function of this protein in the events that take place during embryogenesis and differentiation, we carried out detailed studies on gamma-tubulin during all the developmental stages of Caenorhabditis elegans. We identified the gamma-tubulin gene from this organism and analyzed the localization of the protein by both immunofluorescence and GFP reporter construct. We show that gamma-tubulin association with the centrosome is highly dynamic in mitotic cells, being massively recruited at prophase and released at anatelophase. This accumulation in mitotic centrosomes is dramatic during the first embryonic divisions. We provide the first description of the morphological changes at the centrosome level during the orientation of the mitotic spindle and the flattening of the posterior aster. Loss of function of the gamma-tubulin gene by RNAi induces a strong polyploidization of mitotic germ cells and embryos, but does not affect meiosis and pronuclear migration. In addition, we demonstrate the prominent redistribution of gamma-tubulin in adults at basal bodies of amphid and phasmid neurons, and at the apical membrane of polarized intestinal cells.

scholarly journals Toward a molecular genetic analysis of spermatogenesis in Drosophila melanogaster: characterization of male-sterile mutants generated by single P element mutagenesis.

Genetics ◽  
1993 ◽  
Vol 135 (2) ◽  
pp. 489-505 ◽  
Author(s):  
D H Castrillon ◽  
P Gönczy ◽  
S Alexander ◽  
R Rawson ◽  
C G Eberhart ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
P Element ◽  
Male Sterile ◽  
Germline Proliferation ◽  
Complementation Groups ◽  
Mutant Phenotypes

Abstract We describe 83 recessive autosomal male-sterile mutations, generated by single P element mutagenesis in Drosophila melanogaster. Each mutation has been localized to a lettered subdivision of the polytene map. Reversion analyses, as well as complementation tests using available chromosomal deficiencies, indicate that the insertions are responsible for the mutant phenotypes. These mutations represent 63 complementation groups, 58 of which are required for spermatogenesis. Phenotypes of the spermatogenesis mutants were analyzed by light microscopy. Mutations in 12 loci affect germline proliferation, spermatocyte growth, or meiosis. Mutations in 46 other loci disrupt differentiation and maturation of spermatids into motile sperm. This collection of male-sterile mutants provides the basis for a molecular genetic analysis of spermatogenesis.

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