scholarly journals DEVELOPMENTAL GENETICS OF THE 2E-F REGION OF THE DROSOPHILA X CHROMOSOME: A REGION RICH IN "DEVELOPMENTALLY IMPORTANT" GENES

Genetics ◽  
1984 ◽  
Vol 108 (3) ◽  
pp. 559-572
Author(s):  
Norbert Perrimon ◽  
Lee Engstrom ◽  
Anthony P Mahowald
Keyword(s):  
Cell Viability ◽  
Germ Cell ◽  
X Chromosome ◽  
Maternal Effect ◽  
Germ Line ◽  
Normal Activity ◽  
Developmental Genetics ◽  
Viability Analysis ◽  
Egg Chambers ◽  
Complementation Groups

ABSTRACT We have analyzed the 2E1-3A1 area of the X chromosome with special attention to loci related to embryogenesis. Published maps indicate that this chromosomal segment contains ten bands. Our genetic analysis has identified 11 complementation groups: one recessive visible (prune), two female steriles and eight lethals. One of the female sterile loci is fs(1)k10 for which homozygous females produce both egg chambers and embryos with a dorsalized morphology. The second female sterile is the paternally rescuable fs(1) pecanex in which unrescued embryos have a hypertrophic nervous system. Of the eight lethal complementation groups two are recessive embryonic lethals: hemizygous giant (gt) embryos possess segmental defects, and hemizygous crooked neck (crn) embryos exhibit a twisted phenotype. Analysis of these mutations in the female germ line indicates that gt does not show a maternal effect, whereas normal activity of crn is required for germ cell viability. Analysis of the maternal effect in germ line clones of the remaining six recessive lethal complementation groups indicates that four are required for germ cell viability and one produces ambiguous results for survival of the germ cells. The remaining, l(1) pole hole, is a recessive early pupal lethal in which embryos derived from germ line clones and lacking wild-type gene activity exhibit the "torso" or "pole hole" phenotype.

scholarly journals DEVELOPMENTAL GENETICS OF THE 2C-D REGION OF THE DROSOPHILA X CHROMOSOME

Genetics ◽  
1985 ◽  
Vol 111 (1) ◽  
pp. 23-41 ◽  
Author(s):  
Norbert Perrimon ◽  
Lee Engstrom ◽  
Anthony P Mahowald
Keyword(s):  
X Chromosome ◽  
Group Analysis ◽  
Normal Activity ◽  
Complementation Group ◽  
Developmental Genetics ◽  
Additional Information ◽  
D Region ◽  
Complementation Groups ◽  
Homeotic Mutation ◽  
Mitotic Figures

ABSTRACT We have conducted a genetic and developmental analysis of genes within the 2C-D area of the X chromosome. Phenotypes of 33 mutations representing nine adjacent complementation groups including eight recessive lethals and one visible homeotic mutation (polyhomeotic) are described. Germline clonal analysis of the eight zygotic lethals has revealed three types of gene requirements: (1) normal activity at two pupal lethal loci (corkscrew and C204) and one larval lethal locus (ultraspiracle) is required for normal embryogenesis; (2) normal activity at three larval lethal loci (DF967, VE651 and Pgd) is required for normal oogenesis; and (3) activity at only one locus (EA82), a larval lethal, appears to have no maternal requirement. Ambiguous results were obtained for the GF316 lethal complementation group. Analysis of mitotic figures of the pupal lethals indicates that C204 disrupts an essential mitotic function. This result correlates with the preblastoderm arrest observed among embryos derived from germline clones of C204. Embryos derived from germline clones of corkscrew (csw) exhibit a "twisted" phenotype. The recessive lethal ultraspiracle (usp) disrupts the organization of the posterior tip of the larva both zygotically and maternally: second instar usp/Y larvae derived from heterozygous usp/+ mothers possess an extra set of spiracles, whereas usp/Y embryos derived from females possessing a germline clone (usp/usp) exhibit a localized ventral defect in the ninth or posterior eighth abdominal segment. Analysis of the phenotypes of deficiency-hemizygous embryos indicates the presence of an embryonic zygotic lethal locus, as yet unidentified, which produces central nervous system and ventral hypoderm degeneration. Additional information on the genetic organization of loci within the adjacent 2E area are also described. The implications of this analysis to our understanding of the maternal of zygotic lethal loci in development are discussed.

scholarly journals Developmental genetics of loci at the base of the X chromosome of Drosophila melanogaster.

Genetics ◽  
1989 ◽  
Vol 121 (2) ◽  
pp. 313-331 ◽  
Author(s):  
N Perrimon ◽  
D Smouse ◽  
G L Miklos
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Developmental Genetics ◽  
Optic Lobes ◽  
Sterile Technique ◽  
Specific Subset ◽  
Dominant Female ◽  
Clone Analysis ◽  
Complementation Groups ◽  
Developmental Analysis

Abstract We have conducted a genetic and developmental analysis of the 26 contiguous genetic complementation groups within the 19D3-20F2 interval of the base of the X chromosome, a region of 34 polytene bands delimited by the maroon-like and suppressor of forked loci. Within this region there are four loci which cause visible phenotypes but which have little or no effect on zygotic viability (maroon-like, little fly, small optic lobes and sluggish). There are 22 loci which, when mutated, are zygotic lethals and three of these, legless/runt, folded gastrulation and 13E3, have severe effects on embryonic development. In addition, three visible phenotypes have been defined only by overlapping deficiencies (melanized-like, tumorous head, and varied outspread). We have analyzed the lethal phases and maternal requirement of 58 mutations at 22 of the zygotic lethal loci by means of germline clone analysis using the dominant female sterile technique. Additionally, all lethal complementation groups, as well as a specific subset of deficiencies, have been studied histologically for defects in the development of the central and peripheral embryonic nervous systems.

scholarly journals LETHALITY PATTERNS AND MORPHOLOGY OF SELECTED LETHAL AND SEMI-LETHAL MUTATIONS IN THE ZESTE-WHITE REGION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1972 ◽  
Vol 72 (4) ◽  
pp. 615-638 ◽  
Author(s):  
M P Shannon ◽  
T C Kaufman ◽  
M W Shen ◽  
B H Judd
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
X Chromosome ◽  
Pattern Analysis ◽  
Salivary Gland Chromosome ◽  
Developmental Genetics ◽  
Morphological Attributes ◽  
White Region ◽  
Lethal Mutations ◽  
Complementation Groups

ABSTRACT Aspects of the developmental genetics of lethal and semi-lethal mutants representing 13 complementation groups (cistrons) in the 3A-3C region of the X chromosome of Drosophila melanogaster are given. Each of these cistrons is associated with a particular chromomere in the salivary gland chromosome. Mutants within each cistron have similar lethality patterns and morphological attributes, and the characteristics of a given cistron are distinct with respect to other cistrons. These results provide additional evidence that only one function is associated with each chromomere.—The results of the lethality pattern analysis are also compared with previous studies of lethal mutants of Drosophila.

scholarly journals VIABILITY OF FEMALE GERM-LINE CELLS HOMOZYGOUS FOR ZYGOTIC LETHALS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1983 ◽  
Vol 103 (2) ◽  
pp. 235-247
Author(s):  
Antonio Garcia-Bellido ◽  
Leonard G Robbins
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Germ Line ◽  
Epidermal Cells ◽  
Chromosome Band ◽  
X Chromosomes ◽  
Different Types ◽  
Complementation Groups ◽  
Female Germ Line ◽  
Embryonic Arrest

ABSTRACT We have analyzed the viability of different types of X chromosomes in homozygous clones of female germ cells. The chromosomes carried viable mutations, single-cistron zygotic-lethal and semi-lethal mutations, or small (about six chromosome band) deletions. Homozygous germ-line clones were produced by recombination in females heterozygous for an X-linked, dominant, agametic female sterile. All the zygotic-viable mutants are also viable in germ cells. Of 16 deletions tested (uncovering a total of 93 bands) only 2 (of 4 and 5 bands) are germ-cell viable. Mutations in 15 lethal complementation groups in the zeste-white region were tested. When known, the most extreme alleles at each locus were tested. Only in five loci (33%) were the mutants viable in the germ line. Similar studies of the same deletions and point-mutant lethals in epidermal cells show that 42% of the bands and 77% of the lethal alleles are viable. Thus, germ-line cells have more stringent cell-autonomous genetic requirements than do epidermal cells. The eggs recovered from clones of three of the germ-cell viable zw mutations gave embryos arrested early in embryogenesis, although genotypically identical embryos derived from heterozygous oogonia die as larvae or even hatch as adult escapers. For two genes, homozygosis of the mutations tested also caused embryonic arrest of heterozygous female embryos, and in one case, the eggs did not develop at all. Germ-line clones of one quite leaky mutation gave eggs that were indistinguishable from normal. The abundance of genes whose products are required for oogenesis, whose products are required in the oocyte, and whose activity is required during zygotic development is discussed.

scholarly journals Flamenco, a gene controlling the gypsy retrovirus of Drosophila melanogaster.

Genetics ◽  
1995 ◽  
Vol 139 (2) ◽  
pp. 697-711 ◽  
Author(s):  
N Prud'homme ◽  
M Gans ◽  
M Masson ◽  
C Terzian ◽  
A Bucheton
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Maternal Effect ◽  
High Frequency ◽  
Mutant Allele ◽  
Null Allele ◽  
Germ Line ◽  
Endogenous Retrovirus ◽  
Host Gene ◽  
Dominant Mutation

Abstract Gypsy is an endogenous retrovirus of Drosophila melanogaster. It is stable and does not transpose with detectable frequencies in most Drosophila strains. However, we have characterized unstable strains, known as MG, in which it transposes at high frequency. These stocks contain more copies of gypsy than usual stocks. Transposition results in mutations in several genes such as ovo and cut. They are stable and are due to gypsy insertions. Integrations into the ovoD1 female sterile-dominant mutation result in a null allele of the gene and occurrence of fertile females. This phenomenon, known as the ovoD1 reversion assay, can be used to quantitate gypsy activity. We have shown that the properties of MG strains result from mutation of a host gene that we called flamenco (flam). It has a strict maternal effect on gypsy mobilization: transposition occurs at high frequency only in the germ line of the progeny of females homozygous for mutations of the gene. It is located at position 65.9 (20A1-3) on the X chromosome. The mutant allele present in MG strains is essentially recessive. Flamenco seems to control the infective properties of gypsy.

scholarly journals Lack of GAGA protein in Trl mutants causes massive cell death in Drosophila spermatogenesis and oogenesis

2021 ◽  
Vol 25 (3) ◽  
pp. 292-300
Author(s):  
N. V. Dorogova ◽  
A. E. Zubkova ◽  
E. V. Fedorova ◽  
E. U. Bolobolova ◽  
E. M. Baricheva
Keyword(s):  
Cell Death ◽  
Germ Cell ◽  
Target Genes ◽  
Germ Line ◽  
Gaga Factor ◽  
Cellular Functions ◽  
Massive Cell Death ◽  
Egg Chambers ◽  
Drosophila Protein ◽  
Massive Cell

Drosophila protein GAGA (GAF) is a factor of epigenetic transcription regulation of a large group of genes with a wide variety of cellular functions. GAF is encoded by the Trithorax-like (Trl) gene, which is important for the formation of various organs and tissues at all stages of ontogenesis. In our previous works, we showed that this protein is necessary for the development of the reproductive system, both in males and females of Drosophila. Decreased expression of the Trl gene led to multiple disorders of spermatogenesis and oogenesis. One of the significant disorders was associated with massive degradation and loss of cells in the germline. In this work, we carried out a more detailed cytological study to determine what type of germ cell death is characteristic of Trl mutants, and whether there are disturbances or changes in this process compared to the norm. The results obtained showed that the lack of GAF protein causes massive germ cell death in both females and males of Drosophila, but this death manifests itself in different ways, depending on the sex. In Trl females, this process does not differ phenotypically from the norm. In the dying egg chambers, signs of apoptosis and autophagy were revealed, as well as morphological features that are characteristic of the wild type. In males, Trl mutations induce mass germ cell death through autophagy, which is not typical of Drosophila spermatogenesis, and has not been previously described, neither in the norm nor in other genes’ mutations. Thus, GAF lack in Trl mutants leads to increased germ cell death through apoptosis and autophagy. Ectopic cell death and germ line atrophy are probably associated with impaired expression of the GAGA factor target genes, among which there are genes that regulate both apoptosis and autophagy.

scholarly journals Oxygen tension modulates the mitochondrial genetic bottleneck and influences the segregation of a heteroplasmic mtDNA variant in vitro

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mikael G. Pezet ◽  
Aurora Gomez-Duran ◽  
Florian Klimm ◽  
Juvid Aryaman ◽  
Stephen Burr ◽  
...  
Keyword(s):  
Germ Cell ◽  
Oxygen Tension ◽  
Germ Line ◽  
Embryonic Stem ◽  
Mitochondrial Diseases ◽  
Genetic Bottleneck ◽  
Cellular Mechanisms ◽  
Germ Cell Specification ◽  
Vitro Model

AbstractMost humans carry a mixed population of mitochondrial DNA (mtDNA heteroplasmy) affecting ~1–2% of molecules, but rapid percentage shifts occur over one generation leading to severe mitochondrial diseases. A decrease in the amount of mtDNA within the developing female germ line appears to play a role, but other sub-cellular mechanisms have been implicated. Establishing an in vitro model of early mammalian germ cell development from embryonic stem cells, here we show that the reduction of mtDNA content is modulated by oxygen and reaches a nadir immediately before germ cell specification. The observed genetic bottleneck was accompanied by a decrease in mtDNA replicating foci and the segregation of heteroplasmy, which were both abolished at higher oxygen levels. Thus, differences in oxygen tension occurring during early development likely modulate the amount of mtDNA, facilitating mtDNA segregation and contributing to tissue-specific mutation loads.

Major sex-determining genes and the control of sexual dimorphism in Caenorhabditis elegans

Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 625-637 ◽  
Author(s):  
Jonathan Hodgkin ◽  
Andrew D. Chisholm ◽  
Michael M. Shen
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
X Chromosome ◽  
Germ Line ◽  
Cell Lineage ◽  
Regulatory Genes ◽  
Nematode Caenorhabditis Elegans ◽  
X Chromosomes ◽  
The Many ◽  
Lineage Analysis

Sex determination in Caenorhabditis elegans involves a cascade of major regulatory genes connecting the primary sex determining signal, X chromosome dosage, to key switch genes, which in turn direct development along either male or female pathways. Animals with one X chromosome (XO) are male, while animals with two X chromosomes (XX) are hermaphrodite: hermaphrodite development occurs because the action of the regulatory genes is modified in the germ line so that both sperm and oocytes are made inside a completely female soma. The regulatory genes are being examined by both genetic and molecular means. We discuss how these major genes, in particular the last switch gene in the cascade, tra-1, might regulate the many different sex-specific events that occur during the development of the hermaphrodite and of the male.Key words: nematode, Caenorhabditis elegans, sex determination, sexual differentiation, cell lineage analysis.

scholarly journals Human germ cell formation in xenotransplants of induced pluripotent stem cells carrying X chromosome aneuploidies

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Antonia A. Dominguez ◽  
H. Rosaria Chiang ◽  
Meena Sukhwani ◽  
Kyle E. Orwig ◽  
Renee A. Reijo Pera
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Induced Pluripotent Stem Cells ◽  
X Chromosome ◽  
Pluripotent Stem Cells ◽  
Cell Formation ◽  
Induced Pluripotent ◽  
Germ Cell Formation

Roles of Anti-Müllerian hormone (Amh) and its duplicates in sex determination and germ cell proliferation of Nile tilapia

Genetics ◽  
2021 ◽  
Author(s):  
Xingyong Liu ◽  
Shengfei Dai ◽  
Jiahong Wu ◽  
Xueyan Wei ◽  
Xin Zhou ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Sex Determination ◽  
Germ Cell ◽  
Y Chromosome ◽  
X Chromosome ◽  
Nile Tilapia ◽  
Critical Period ◽  
Sex Reversal ◽  
Homozygous Mutation ◽  
Germ Cell Proliferation

Abstract Duplicates of amh are crucial for fish sex determination and differentiation. In Nile tilapia, unlike in other teleosts, amh is located on X chromosome. The Y chromosome amh (amh△-y) is mutated with 5 bp insertion and 233 bp deletion in the coding sequence, and tandem duplicate of amh on Y chromosome (amhy) has been identified as the sex determiner. However, the expression of amh, amh△-y and amhy, their roles in germ cell proliferation and the molecular mechanism of how amhy determines sex is still unclear. In this study, expression and functions of each duplicate were analyzed. Sex reversal occurred only when amhy was mutated as revealed by single, double and triple mutation of the three duplicates in XY fish. Homozygous mutation of amhy in YY fish also resulted in sex reversal. Earlier and higher expression of amhy/Amhy was observed in XY gonads compared with amh/Amh during sex determination. Amhy could inhibit the transcription of cyp19a1a through Amhr2/Smads signaling. Loss of cyp19a1a rescued the sex reversal phenotype in XY fish with amhy mutation. Interestingly, mutation of both amh and amhy in XY fish or homozygous mutation of amhy in YY fish resulted in infertile females with significantly increased germ cell proliferation. Taken together, these results indicated that up-regulation of amhy during the critical period of sex determination makes it the sex-determining gene, and it functions through repressing cyp19a1a expression via Amhr2/Smads signaling pathway. Amh retained its function in controlling germ cell proliferation as reported in other teleosts, while amh△-y was nonfunctionalized.

Sign in / Sign up

Export Citation Format

Share Document