Allele Dmel\Hmr²

General Information
Symbol	Dmel\Hmr²	Species	D. melanogaster
Name		FlyBase ID	FBal0144828
Feature type	allele	Associated gene	Dmel\Hmr

Map ( GBrowse )
Allele class
Mutagen
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
Mutations Mapped to the Genome

Type Location Additional Notes References point mutation X:10,488,449..10,488,449 evidence=experimental na_change=G10439634A pr_change=E371K\|BcDNA:LD22117-PB reported_pr_change=E371K comment=One of two amino acid changes in the Hmr^AB mutant. Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change. (Barbash et al., 2003) point mutation X:10,487,980..10,487,980 evidence=experimental na_change=G10439165C pr_change=G527A\|BcDNA:LD22117-PB reported_pr_change=G527A comment=One of two amino acid changes in the Hmr^AB mutant. Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change. (Barbash et al., 2003)
Associated Sequence Data
DDBJ / EMBL / GenBank	DNA sequence Protein sequence Name AY260056 AAO85036

UniProtKB/Swiss-Prot
UniProtKB/TrEMBL

Progenitor genotype
Nature of the lesion	Statement Reference Amino acid replacement: E371K. Amino acid replacement: G527A. (Barbash et al., 2003)
Carried on aberration	In(1)AB (Aruna et al., 2009)
Cytology
Phenotypic Data
Phenotypic Class
	female sterile \| partially (with Hmr^Df) (Aruna et al., 2009)
Phenotype Manifest In

Detailed Description
	Statement Reference Hmr[2]/Hmr[Df] females have significantly reduced fertility compared to controls. (Aruna et al., 2009) Hmr[2] suppresses hybrid male lethality of hybrid sons of crosses between D.melanogaster females and D.simulans males. This hybrid rescue is not suppressed if the hybrids also carry Dsim\Hmr[+t8.6] or Dmau\Hmr[+t9.4]. The sterility of hybrid daughters of crosses between D.melanogaster females and D.simulans males is suppressed by Hmr[2]. This Hmr[2]-dependent rescue of hybrid female sterility is not affected if the hybrids also carry Dsim\Hmr[+t8.6]. (Barbash et al., 2004) Hmr[2] can rescue to viability the hybrid male progeny of D.melanogaster females crossed to D.simulans males, but these hybrid males remain sterile and have rudimentary testes. Hmr[2] can rescue the sterility of hybrid female progeny of D.melanogaster females crossed to D.simulans males. The degree of rescue of oogenesis depends on the D.simulans stock used, suggesting that D.simulans stocks are polymorphic for factors that allow rescue of the hybrids. No rescue of fertility is seen in female hybrids derived from Hmr[2] D.melanogaster females crossed to D.simulans males of the C167.4 strain. However, hybrid females derived from the reciprocal cross (C167.4 D.simulans females mated to Hmr[2] D.melanogaster males) do show rescue of fertility, suggesting that the genetic bases of fertility rescue in the two directions of crossing are at least partially distinct. Hybrid males derived from a cross of Hmr[2] D.melanogaster females mated to D.mauritiana males are sterile and have rudimentary testes. Hmr[2] can rescue the sterility of hybrid female progeny of D.melanogaster females crossed to D.mauritiana males. The degree of rescue of fertility depends on the D.mauritiana stock used. Little or no rescue of fertility is seen in female hybrids derived from Hmr[2] D.melanogaster females crossed to D.sechellia males (10 D.sechellia stocks have been tested). (Barbash and Ashburner, 2003) Hybrid daughters (from a cross of D.melanogaster females to D.simulans or D.mauritiana males) that carry two D.melanogaster X chromosomes are lethal. This lethality is partially suppressed by one copy of D.melanogaster Hmr[2]. (Barbash et al., 2000) Crosses between D.simulans strain C167.4 females and D.melanogaster Hmr[2] males result in hybrids of which females are fertile and males are sterile. The hybrid males have tiny atrophied testes containing no sperm and often have an abnormal abdomen phenotype. All the hybrid females in this cross typically produce eggs, although the degree of rescue of fertility is variable; some females contain only a few, very early stage egg clusters, while in other females oogenesis occurs normally in most cysts. There is a significant decrease in the quality and quantity of eggs and ovarioles containing germline cells as the hybrid females age. Eggs from older females may be ventralised. Crosses between D.simulans strain Tsimbazaza females and D.melanogaster Hmr[2] males result in hybrids of which females and males are sterile. The hybrid males have tiny atrophied testes containing no sperm and often have an abnormal abdomen phenotype. A small number of females produce a few eggs (approximately 2 per ovary), although in most cases their ovaries are completely atrophied. The females contain germline cells, but they often have an unusual "doughnut" phenotype, with the germline cells being unusually large with a layer of smaller cells (likely to be follicle cells) surrounding each of the large cells. A large clump of DNA is visible inside the "doughnut" upon nuclear staining and looks like an aggregation of several large nuclei. Eggs may be ventralised. Crosses between D.simulans C167.4 or Tsimbazaza males and D.melanogaster Hmr[2] females result in hybrids of which males that survive to adulthood often show a variety of somatic defects (including abnormal abdomens, notched wings, knobby wings and stumpy legs). The frequency of the defects varies with the parental D.simulans strain. Hybrid progeny are sterile, except for hybrid females from crosses involving C167.4 males; 41% of these females show some egg production, although they produce only approximately one egg per ovary and the eggs are small, ventralised or otherwise abnormal. Early stage egg clusters often show the germline cell "doughnut" phenotype. (Hollocher et al., 2000) Hmr[2] rescues the mitotic chromosome decondensation defect seen in the larval brain neuroblasts of male hybrids produced from a cross between D.melanogaster females and D.mauritiana males. (Orr et al., 1997) Rare female hybrids from D.simulans strain C167.4 females and Hmr[2] males have well developed ovaries that contain large number of mature eggs. The reciprocal cross fails to produce fertile female hybrids, indicating a maternal effect for the female sterility rescue (due to maternal contributions from the nuclear genome). No hybrid male sterility rescue is observed, males have rudimentary testes with no advanced stages of spermatogenesis. Lower levels of hybrid female fertility were also observed in crosses involving D.simulans strains Oxnard and vermilion to Hmr[2]. (Davis et al., 1996) Rescues species hybrids that are normally inviable; rescues hybrid females from a cross of D.melanogaster Hmr[2]/Y males to sibling species females, as well as hybrid males from a cross of Hmr[2] females to sibling species males. (Hutter et al., 1990)
External Data
Linkouts
Interactions
Phenotypic Class
Phenotype Manifest In
Additional Comments
Genetic Interactions
Statement Reference
Xenogenetic Interactions
Statement Reference
Complementation & Rescue Data
Comments
Stocks ( 0 )

Notes on Origin
Discoverer
	The In(1)AB chromosome carries a lesion in Hmr (Hmr[2]), which is responsible for the hybrid rescue associated with the chromosome. (Aruna et al., 2009)
Comments
	FBrf0051988 reported that the In(1)AB chromosome (which carries the Hmr[2] allele) can prevent the larval lethality of hybrid males from crosses between D.simulans males and D.melanogaster females and the embryonic lethality of hybrid females from the reciprocal cross. A known Zhr[+] allele was recombined onto the In(1)AB chromosome, and the resulting chromosome can only prevent the hybrid male larval lethality, thus the two rescuing actions reported for the In(1)AB chromosome are not due to a single gene. (Sawamura et al., 1993) FlyBase curator comment: It has been shown that the hybrid rescue associated with the In(1)AB chromosome is due to a lesion on the chromosome that affects Hmr function (Hmr[2]) and which is not associated with either inversion breakpoint (see FBrf0207733). Thus all information regarding hybrid rescue that had previously been reported in the literature for In(1)AB has been moved in FlyBase from the In(1)AB aberration report to the Hmr[2] allele report. (FlyBase, 1992-)
External Crossreferences & Linkouts
Other Crossreferences

Linkouts

Synonyms & Secondary IDs ( 2 )
Reported As
Symbol Synonym	Hmr² (Aruna et al., 2009) Hmr^AB
Name Synonym
Secondary FlyBase IDs

References ( 12 )
Research paper	Aruna et al., 2009, Genetics 181(4): 1437--1450 Reduced fertility of Drosophila melanogaster hybrid male rescue (Hmr) mutant females is partially complemented by Hmr orthologs from sibling species. [FBrf0207733] Barbash et al., 2004, PLoS Biol. 2(6): 0839--0848 Functional divergence caused by ancient positive selection of a Drosophila hybrid incompatibility locus. [FBrf0179125] Barbash et al., 2003, Proc. Natl. Acad. Sci. USA 100(9): 5302--5307 A rapidly evolving MYB-related protein causes species isolation in Drosophila. [FBrf0159301] Barbash and Ashburner, 2003, Genetics 163(1): 217--226 A novel system of fertility rescue in Drosophila hybrids reveals a link between hybrid lethality and female sterility. [FBrf0155814] Barbash et al., 2000, Genetics 154(4): 1747--1771 The Drosophila melanogaster Hybrid male rescue gene causes inviability in male and female species hybrids. [FBrf0127000] Hollocher et al., 2000, J. exp. Zool. 288(3): 205--218 Characterization of defects in adult germline development and oogenesis of sterile and rescued female hybrids in crosses between Drosophila simulans and Drosophila melanogaster. [FBrf0131316] Zhang et al., 1999, Genetics 153(2): 891--903 stress sensitive B encodes an Adenine Nucleotide Translocase in Drosophila melanogaster. [FBrf0111529] Orr et al., 1997, Genetics 145(4): 1031--1040 The developmental genetics of hybrid inviability: a mitotic defect in Drosophila hybrids. [FBrf0093179] Davis et al., 1996, Nature 380(6570): 157--159 Rescue of hybrid sterility in crosses between D. melanogaster and D. simulans. [FBrf0086371] Sawamura et al., 1993, Genetics 133(2): 307--313 Hybrid lethal systems in the Drosophila melanogaster species complex. [FBrf0058561] Hutter et al., 1990, Genetics 124: 909--920 A genetic basis for the inviability of hybrids between sibling species of Drosophila. [FBrf0051988]
FlyBase analysis	FlyBase, 1992-, FlyBase curation FlyBase curation. [FBrf0105495]

Allele Dmel\Hmr2

Allele Dmel\Hmr²