Allele Dmel\mh¹

General Information
Symbol	Dmel\mh¹	Species	D. melanogaster
Name		FlyBase ID	FBal0012241
Feature type	allele	Associated gene	Dmel\mh

Allele class
Mutagen	ethyl methanesulfonate
Recent Updates
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FB2012_01
FB2011_10
All updates	Click here to see a list of all updates to this record from FB2010_08 and on.
Nature of the Allele
Allele class
Mutagen	ethyl methanesulfonate
Mutations Mapped to the Genome

Type Location Additional Notes References
Associated Sequence Data
DDBJ / EMBL / GenBank	DNA sequence Protein sequence Name

UniProtKB/Swiss-Prot
UniProtKB/TrEMBL

Progenitor genotype
Nature of the lesion	Statement Reference
Cytology
Phenotypic Data
Phenotypic Class
	female sterile (Freeman and Glover, 1987) lethal \| embryonic stage \| maternal effect \| recessive (Loppin et al., 2001) mitotic cell cycle defective \| maternal effect \| recessive (Loppin et al., 2001)
Phenotype Manifest In
	cycle 1 embryo & mitosis & nuclear chromosome \| maternal effect (Loppin et al., 2001) cycle 1 embryo \| maternal effect (Loppin et al., 2001) embryonic/first instar larval cuticle \| maternal effect (Loppin et al., 2001) embryonic abdominal segment \| maternal effect (Loppin et al., 2001) embryonic head \| maternal effect (Loppin et al., 2001) telson \| maternal effect (Loppin et al., 2001)
Detailed Description
	Statement Reference Embryos derived from homozygous females crossed with wild-type males never hatch. 22% of the embryos reach late embryogenesis and deposit a cuticle before dying. The cuticles have head defects, antero-dorsal holes, missing abdominal segments and an internalised telson. These late dying embryos are haploid gynogenetic embryos. Most eggs derived from homozygous females crossed with wild-type males contain a sperm tail. Female meiosis in the eggs produces a female pronucleus and three polar bodies, as in control eggs. The pronuclei are apposed in early fertilised eggs derived from homozygous females crossed with wild-type males, and the pronuclei enter the first division asynchronously, as occurs in wild-type fertilised eggs. The gonomeric division is always defective in eggs derived from homozygous females crossed with wild-type males. In anaphase of the first division, only one-half of the chromosomes (the maternal complement) migrate towards the spindle poles, whereas the other half (the paternal complement) lag behind on the metaphase plate. In telophase, a chromatin bridge of paternal origin is formed between the two daughter nuclei. At the end of the first division, the bridge breaks down and the late chromatin segregates at random between the two zygotic nuclei. This results in a high frequency of aneuploidy in interphase of nuclear cycle 2. Two major phenotypic classes are seen in the second embryonic mitosis. About half of the embryos show a similar phenotype to the first mitotic division, with the paternal chromosomes lagging behind. The other embryos appear aneuploid as they contain disorganised and fragmented chromosomes. The presence of lagging paternal chromatin is occasionally observed in the third nuclear cycle, but not in older embryos. The gonomeric spindle has a centrosome at each pole and appears to adapt well to the asynchrony of both sets of parental chromosomes during mitosis. The lagging paternal chromatin in telophase of the first mitotic division is surrounded by a nuclear lamina that is distinct from the lamina present around the maternal chromatin. At the end of the first division, daughter nuclei of maternal and paternal origin are often physically separated by their respective nuclear lamina. (Loppin et al., 2001) The male pronucleus is unable to develop in the cytoplasm of embryos from homozygous females. In embryos from females doubly homozygous for mh¹ and gnu³⁰⁵ male-derived DNA is replicated to approximately the same extent as female-derived DNA. (Freeman and Glover, 1987) Homozygous mh females are fertile at 18^oC but at 25^oC they are sterile; irrespective of the males used in cross, nuclei of developing embryos appear to be X-bearing and haploid. 183/200 eggs developed to blastoderm; gastrulation was abnormal; 22 embryos gave evidence of segmentation and muscular movement. Nuclei from such embryos injected into normal early embryos are capable of developing into patches of tissue, some of which produce structures of normal number and size and are presumably diploid, some of which produce increased numbers of smaller-than-normal structures and are presumably haploid and a few of which are mixed. Haploid tissue with female phenotype found in basitarsus, tergites and terminalia. Nuclear division cycles of haploid embryos 2.1 min. longer than wild type; such embryos undergo an extra nucleus division in the syncitial blastoderm, possibly to achieve a proper nuclear: cytoplasmic ratio prior to cellularization (Edgar, Kichle, and Schuberger, 1986). Haploid cell cultures established from 25^oC embryos (Debec, 1978). Haploid cells and their diploidized derivatives lack centrioles (Debec, Szollosi and Sollosc, 1982). temperature-sensitive female-sterile
External Data
Linkouts
Interactions
Phenotypic Class
Phenotype Manifest In
Additional Comments
Genetic Interactions
Statement Reference Fertilised eggs from double mutant Hira^185b mh¹ females contain a round condensed male pronucleus indistinguishable from that of Hira^185b single mutants. The four pairs of maternal sister chromatids separate in anaphase of the first mitosis and bridges in telophase are not observed more frequently than controls. A spindle with centrosomes at both poles containing the haploid set of paternal chromosomes is seen in eggs derived from mh¹ Klp3A³ females as in eggs derived from Klp3A³ females. (Loppin et al., 2001)
Xenogenetic Interactions
Statement Reference
Complementation & Rescue Data
Comments
Stocks ( 1 )
Bloomington	7130 y¹ w^a mh¹/FM7a
Notes on Origin
Discoverer

External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 5 )
Reported As
Symbol Synonym	fs(1)1182 (Perrimon et al., 1986) fs(1)A1182 mh (Loppin et al., 2001, Freeman and Glover, 1987) mh¹ mh¹¹⁸² (Liu et al., 1997)
Name Synonym
Secondary FlyBase IDs

References ( 4 )
Research paper	Loppin et al., 2001, Dev. Biol. 231(2): 383--396 Paternal chromosome incorporation into the zygote nucleus is controlled by maternal haploid in Drosophila. [FBrf0134547] Liu et al., 1997, Dev. Biol. 184(2): 187--196 Formation of the male pronuclear lamina in Drosophila melanogaster. [FBrf0093577] Freeman and Glover, 1987, Genes Dev. 1(9): 924--930 The gnu mutation of Drosophila causes inappropriate DNA synthesis in mutant and fertilized eggs. [FBrf0063443] Perrimon et al., 1986, Genetics 113: 695--712 X-linked female-sterile loci in Drosophila melanogaster. [FBrf0044470]

Allele Dmel\mh1

Allele Dmel\mh¹