Observations on chromosomal male sterility in Drosophila melanogaster

1984 ◽  
Vol 26 (1) ◽  
pp. 67-77
Author(s):  
James. C. Stone
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Functional Unit ◽  
Primary Spermatocyte ◽  
Male Meiosis ◽  
Centromeric Heterochromatin ◽  
Control Element ◽  
Male Sterile ◽  
Cis Acting ◽  
Autosome Translocation

Observations on a variety of metazoans have shown that the X chromosome becomes functionally inactive earlier in male meiosis than the remainder of the genome. Genetic analyses of male-sterile chromosome rearrangements in Drosophila suggest that the X chromosome in this species behaves as a distinct functional unit, and have further suggested that X-chromosome expression is regulated in the primary spermatocyte by a cis-acting control element located in the centromeric heterochromatin. Attempts to test the X-inactivation hypothesis of chromosomal sterility in Drosophila and attempts to map the hypothetical control element are described here. Cytological observations on a male-sterile X-autosome translocation are also discussed.

scholarly journals THE GENETIC AND CYTOLOGICAL ORGANIZATION OF THE Y CHROMOSOME OF DROSOPHILA MELANOGASTER

Genetics ◽  
1981 ◽  
Vol 98 (3) ◽  
pp. 529-548
Author(s):  
James A Kennison
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
X Chromosome ◽  
Male Fertility ◽  
Functional Unit ◽  
Hoechst 33258 ◽  
Genetic Analyses ◽  
Translocation Breakpoints

ABSTRACT Cytological and genetic analyses of 121 translocations between the Y chromosome and the centric heterochromatin of the X chromosome have been used to define and localize six regions on the Y chromosome of Drosophila melanogaster necessary for male fertility. These regions are associated with nonfluorescent blocks of the Y chromosome, as revealed using Hoechst 33258 or quinacrine staining. Each region appears to contain but one functional unit, as defined by failure of complementation among translocations with breakpoints within the same block. The distribution of translocation breakpoints examined appears to be nonrandom, in that breaks occur preferentially in the nonfluorescent blocks and not in the large fluorescent blocks.

scholarly journals MALE-STERILIZING INTERACTIONS BETWEEN DUPLICATIONS AND DEFICIENCIES FOR PROXIMAL X-CHROMOSOME MATERIAL IN DROSOPHILA MELANOGASTER

Genetics ◽  
1981 ◽  
Vol 99 (1) ◽  
pp. 49-64
Author(s):  
Rezaur Rahman ◽  
Dan L Lindsley
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Male Fertility ◽  
Primary Spermatocyte ◽  
Single Factor ◽  
X Chromosomes ◽  
Recessive Lethal ◽  
Lethal Mutations ◽  
Y Chromosomes ◽  
Chromosome Material

ABSTRACT The genetic limits of sixty-four deficiencies in the vicinity of the euchromatic-heterochromatic junction of the X chromosome were mapped with respect to a number of proximal recessive lethal mutations. They were also tested for male fertility in combination with three Y chromosomes carrying different amounts of proximal X-chromosome-derived material (BSYy+, y+Ymal126 and y  +  Ymal  +). All deficiencies that did not include the locus of bb and a few that did were male-fertile in all male-viable Df(1)/Dp(1;Y) combinations. Nineteen bb deficiencies fell into six different classes by virtue of their male-fertility phenotypes when combined with the duplicated Y chromosomes. The six categories of deficiencies are consistent with a formalism that invokes three factors or regions at the base of the X, one distal and two proximal to bb, which bind a substance critical for precocious inactivation of the X chromosome in the primary spermatocyte. Free duplications carrying these regions or factors compete for the substance in such a way that, in the presence of such duplications, proximally deficient X chromosomes are unable to command sufficient substance for proper control of X-chromosome gene activity preparatory to spermatogenesis. We conclude that there is no single factor at the base of the X that is required for the fertility of males whose genotype is otherwise normal.

scholarly journals Recombination between the X and Y chromosomes and the Sxr region of the mouse

1992 ◽  
Vol 60 (3) ◽  
pp. 175-184 ◽  
Author(s):  
Anne McLaren ◽  
Elizabeth Simpson ◽  
Colin E. Bishop ◽  
Michael J. Mitchell ◽  
Susan M. Darling
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Recombination Frequency ◽  
Male Meiosis ◽  
Homologous Region ◽  
Crossing Over ◽  
Female Meiosis ◽  
Unequal Crossing Over ◽  
Y Chromosomes ◽  
Autosome Translocation

SummaryThe Sxr (sex-reversed) region that carries a copy of the mouse Y chromosomal testis-determining gene can be attached to the distal end of either the Y or the X chromosome. During male meiosis, Sxr recombined freely between the X and Y chromosomes, with an estimated recombination frequency not significantly different from 50% in either direction. During female meiosis, Sxr recombined freely between the X chromosome to which it was attached and an X-autosome translocation. A male mouse carrying the original Sxra region on its Y chromosome, and the shorter Sxrb variant on the X, also showed 50% recombination between the sex chromosomes. Evidence of unequal crossing-over between the two Sxr regions was obtained: using five markers deleted from Sxrb, 3 variant Sxr regions were detected in 159 progeny (1·9%). Four other variants (one from the original cross and three from later generations) were presumed to have been derived from illegitimate pairing and crossing-over between Sxrb and the homologous region on the short arm of the Y chromosome. The generation of new variants throws light on the arrangement of gene loci and other markers within the short arm of the mouse Y chromosome.

scholarly journals ORGANIZATION OF THE ROSY LOCUS IN DROSOPHILA MELANOGASTER: FURTHER EVIDENCE IN SUPPORT OF A CIS-ACTING CONTROL ELEMENT ADJACENT TO THE XANTHINE DEHYDROGENASE STRUCTURAL ELEMENT

Genetics ◽  
1979 ◽  
Vol 91 (2) ◽  
pp. 275-293
Author(s):  
M McCarron ◽  
J O'Donnell ◽  
A Chovnick ◽  
B S Bhullar ◽  
J Hewitt ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Control Region ◽  
Large Scale ◽  
Present Report ◽  
Xanthine Dehydrogenase ◽  
Control Element ◽  
Genetic Dissection ◽  
Structural Element ◽  
Cis Acting ◽  
A Site

ABSTRACT The present report summarizes our recent progress in the genetic dissection of an elementary genetic unit in a higher organism, the rosy locus (ry: 3-52.0) in Drosophila melanogaster. Pursuing the hypothesis that the rosy locus includes a noncoding control region, as well as a structural element coding for the xanthine dehydrogenase (XDH) peptide, experiments are described that characterize and map a rosy locus variant associated with much lower than normal levels of XDH activity. Experiments are described that fail to relate this phenotype to alteration in the structure of the XDH peptide, but clearly associate this character with variation in number of molecules of XDH per fly. Large-scale fine-structure recombination experiments locate the genetic basis for this variation in the number of molecules of XDH per fly to a site immediately to the left of the XDH structural element within a region previously designated as the XDH control element. Moreover, experiments clearly separate this "underproducer" variant site from a previously described "overproducer" site within the control region. Examination of enzyme activity in electrophoretic gels of appropriate heterozygous genotypes demonstrates the cis-acting nature of this variation in the number of molecules of XDH. A revision of the map of the rosy locus, structural and control elements is presented in light of the additional mapping data now available.

scholarly journals Inseparability of X-Heterochromatic Functions Responsible for X:Y Pairing, Meiotic Drive, and Male Fertility in Drosophila melanogaster

Genetics ◽  
1987 ◽  
Vol 116 (3) ◽  
pp. 399-407
Author(s):  
Bruce McKee ◽  
Dan L Lindsley
Keyword(s):  
Drosophila Melanogaster ◽  
Male Fertility ◽  
Meiotic Drive ◽  
Male Meiosis ◽  
Recovery Ratio ◽  
Strongly Correlated ◽  
Wild Type ◽  
Autosome Translocation ◽  
Ratio Distortion ◽  
Sperm Recovery

ABSTRACT Deficiencies encompassing part or all of the X heterochromatin of Drosophila melanogaster have been linked to three abnormalities in male meiosis and spermatogenesis: X-Y nondisjunction, skewed sperm recovery ratios favoring sperm with reduced chromatin content, and sterility in males carrying either a Y-autosome translocation or mal  +  Y. In this study, 18 X heterochromatic deficiencies of varying sizes were tested in XY males for their spermatogenic phenotypes. All 18 proved to be either mutant for all three phenotypes or wild type for all three. Although variable among mutant deficiencies, expression levels of all three phenotypes were strongly correlated. Deficiencies that cause high levels of nondisjunction also cause severe recovery ratio distortion and are completely sterile in conjunction with mal  +  Y. Low nondisjunction deficiencies cause comparable mild effects for the other phenotypes. The same deficiencies were also tested in males carrying a large heterochromatic free X duplication Dp(1;f)3. For all deficiencies which induce nondisjunction in XY males, the Y and free duplication pair regularly and the X fails to pair in XYDp males. Drive levels are constant across deficiencies in these males. Thus elimination of variability in the pairing phenotype also eliminates variability in sperm recovery ratios.

scholarly journals NATURE AND CONSEQUENCES OF INDUCED CHROMOSOME DAMAGE IN MAMMALS

Genetics ◽  
1974 ◽  
Vol 78 (1) ◽  
pp. 173-186
Author(s):  
A G Searle
Keyword(s):  
Germ Cells ◽  
Primary Spermatocyte ◽  
Break Point ◽  
Complete Separation ◽  
Point Of View ◽  
Centromeric Heterochromatin ◽  
General Tendency ◽  
Male Sterile ◽  
Balanced Translocation ◽  
Reciprocal Translocations

ABSTRACT There are marked qualitative and quantitative differences in the patterns of chromosomal damage observed after irradiation of spermatogonia, spermatozoa and oocytes of mice. These differences often result from reduced or zero transmission of particular classes of abberration arising in pre-meiotic germ cells. Probably this is the reason why the level of X-chromosomal and autosomal monosomy is not increased after spermatogonial irradiation. Similarly, the reduced transmission of certain d-se deficiencies may help to explain their low F1 frequency after pre-meiotic as compared with later irradiation. Spermatozoal irradiation has revealed no Robertsonian translocations, but has produced some types of reciprocal translocations which apparently are not transmitted to the F1 after spermatogonial treatment because they prevent maturation of the male pre-meiotic germ cell. Thus they cause sterility in males, but not in females. They include X-autosome and Y-autosome translocations, those giving a metacentric or sub-metacentric chromosome (with reciprocal product present) and those in which one break-point is in or near the centromeric heterochromatin while the other is more distally placed. This last group (which grades into male sub-fertile conditions) gives a preponderance of chain configurations (often with one separate univalent) in heterozygotes of both sexes at meiosis and a high incidence of somatic marker chromosomes. Nondisjunction associated with the univalent generates tertiary trisomics, which are usually male-sterile also and may show phenotypic abnormalities. Sterile males with complete separation of X and Y chromosomes have also been reported after mutagenic treatment of meiotic and post-meiotic germ cells. Such separation seems to prevent a primary spermatocyte from forming a secondary one. The usual derivation (in mouse and man) of tertiary trisomics from mothers rather than from fathers may be due to a similar block, together with a general tendency for male heterozygotes for the parental balanced translocation to be sterile or sub-fertile. Mature oocytes tend to resemble spermatoza in the types of aberration produced by irradiation, which include the male-sterile translocation, but more data are needed. Many of the aberrations described contribute to the human cytogenetic load and can be studied in the mouse from this point of view.

scholarly journals A COMPARISON OF HEAT AND INTERCHROMOSOMAL EFFECTS ON RECOMBINATION AND INTERFERENCE IN DROSOPHILA MELANOGASTER

Genetics ◽  
1978 ◽  
Vol 89 (1) ◽  
pp. 65-77
Author(s):  
R F Grell
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Thermal Dissociation ◽  
Temporal Sequence ◽  
The Other ◽  
Centromeric Heterochromatin ◽  
Drosophila Genome ◽  
Chromosome 2 ◽  
Independent Control ◽  
Order Of Magnitude

ABSTRACT Heat and interchromosomal effects on recombination have been compared for 23 regions comprising the predominantly euchromatic portions of the five arms of the Drosophila genome. Patterns of response are strikingly similar, with both modifiers causing proximal and distal increases and minimal effects in the middle of the arms. Changes in interference for the same regions in the presence of the two modifiers reveal little similarity, except for the X chromosome. The question of independent control of interference and recombination, as well as alternatives for their temporal sequence, is discussed. Recombination response to the two modifiers in the centric heterochromatin of chromosoaime 2 is markedly different from that found in euchromatin. The interchromosomal effect is absent here, whereas heat induces an increase roughly an order of magnitude greater than that found in euchromatin and totally unlike the lack of response in the proximal heterochromatin of the X chromosome. It is proposed that the sequestering of DNA satellite I (thermal dissociation 9-20° lower than that of the other major satellites) in the centromeric heterochromatin of chromosome 2 (but not in X or 3) may account for the increase.

scholarly journals TISSUE-SPECIFIC AND PRETRANSLATIONAL CHARACTER OF VARIANTS OF THE ROSY LOCUS CONTROL ELEMENT IN DROSOPHILA MELANOGASTER

Genetics ◽  
1984 ◽  
Vol 108 (4) ◽  
pp. 953-968
Author(s):  
S H Clark ◽  
S Daniels ◽  
C A Rushlow ◽  
A J Hilliker ◽  
A Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Fat Body ◽  
Present Report ◽  
Malpighian Tubules ◽  
Phenotypic Characterization ◽  
Control Element ◽  
Structural Element ◽  
Tissue Specific ◽  
Cis Acting

ABSTRACT Prior reports from this laboratory have described the experimental basis for our understanding of the genetic organization of the rosy locus (ry:3-52.0) of Drosophila melanogaster, as a bipartite genetic entity consisting of a structural element that codes for the xanthine dehydrogenase (XDH) peptide and a contiguous, cis-acting control element. The present report describes our progress in the analysis of the control element and its variants. Characterization of the control element variants reveals that, with respect to late third instar larval tissue distribution of XDH activity and cross-reacting material, i409H is associated with a large, tissue-specific increase in fat body which is not observed in malpighian tubules. Further data are presented in support of the inference that this differential expression must reflect differential production of XDH-specific RNA transcripts.—Gel blot analyses are described which demonstrate (1) that the phenotypic effects associated with variation in the rosy locus control element relate to differences in accumulation of XDH-specific poly-A+ RNA and (2) do not relate to differences in rosy DNA template numbers.—Experiments are described that provide for unambiguous mapping of control element sites through the use of half-tetrad recombination experiments and the recovery and phenotypic characterization of the reciprocal products of exchange between control element site variants. Thus, we are able to order the sites as follows: kar-i1005 i409-ry.

scholarly journals Expression of a gene duplication encoding conserved sperm tail proteins is translationally regulated in Drosophila melanogaster.

1993 ◽  
Vol 13 (3) ◽  
pp. 1708-1718 ◽  
Author(s):  
M Schäfer ◽  
D Börsch ◽  
A Hülster ◽  
U Schäfer
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Family ◽  
Translational Control ◽  
Germ Line ◽  
Gene Families ◽  
Homologous Gene ◽  
Male Sterile ◽  
Sperm Tail ◽  
Repetitive Motif ◽  
Carboxy Terminal

We have analyzed a locus of Drosophila melanogaster located at 98C on chromosome 3, which contains two tandemly arranged genes, named Mst98Ca and Mst98Cb. They are two additional members of the Mst(3)CGP gene family by three criteria. (i) Both genes are exclusively transcribed in the male germ line. (ii) Both transcripts encode a protein with a high proportion of the repetitive motif Cys-Gly-Pro. (iii) Their expression is translationally controlled; while transcripts can be detected in diploid stages of spermatogenesis, association with polysomes can be shown only in haploid stages of sperm development. The genes differ markedly from the other members of the gene family in structure; they do not contain introns, they are of much larger size, and they have the Cys-Gly-Pro motifs clustered at the carboxy-terminal end of the encoded proteins. An antibody generated against the Mst98Ca protein recognizes both Mst98C proteins in D. melanogaster. In a male-sterile mutation in which spermiogenesis is blocked before individualization of sperm, both of these proteins are no longer synthesized. This finding provides proof of late translation for the Mst98C proteins and thereby independent proof of translational control of expression. Northern (RNA) and Western immunoblot analyses indicate the presence of homologous gene families in many other Drosophila species. The Mst98C proteins share sequence homology with proteins of the outer dense fibers in mammalian spermatozoa and can be localized to the sperm tail by immunofluorescence with an anti-Mst98Ca antibody.

scholarly journals Patterns of DNA Variability at X-Linked Loci in Mus domesticus

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1303-1316
Author(s):  
Michael W Nachman
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
House Mouse ◽  
Recombination Rate ◽  
Nucleotide Diversity ◽  
Mus Domesticus ◽  
Substantial Variation ◽  
Intraspecific Polymorphism ◽  
Recombination Rates ◽  
Interspecific Divergence

Introns of four X-linked genes (Hprt, Plp, Glra2, and Amg) were sequenced to provide an estimate of nucleotide diversity at nuclear genes within the house mouse and to test the neutral prediction that the ratio of intraspecific polymorphism to interspecific divergence is the same for different loci. Hprt and Plp lie in a region of the X chromosome that experiences relatively low recombination rates, while Glra2 and Amg lie near the telomere of the X chromosome, a region that experiences higher recombination rates. A total of 6022 bases were sequenced in each of 10 Mus domesticus and one M. caroli. Average nucleotide diversity (π) for introns within M. domesticus was quite low (π = 0.078%). However, there was substantial variation in the level of heterozygosity among loci. The two telomeric loci, Glra2 and Amg, had higher ratios of polymorphism to divergence than the two loci experiencing lower recombination rates. These results are consistent with the hypothesis that heterozygosity is reduced in regions with lower rates of recombination, although sampling of additional genes is needed to establish whether there is a general correlation between heterozygosity and recombination rate as in Drosophila melanogaster.

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