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Biomedical subjects

R H Baker

Publications and source records attributed to R H Baker.

84 records · Page 5Linked to original sources
PubMedDate not supplied

Inheritance of two new eye mutants in a mosquito. Brown and abnormal eye in Culex tritaeniorhynchus.

The genetic analysis of two new mutants, brown and abnormal eye, is presented. The data indicate that both mutants are recessive and under the control of loci in linkage group III. The gene sequence for linkage group III is cl-Adh-s-bw-ae. The total length of linkage group III is now approximately 48 map units. Mosquitoes homozygous for both brown and rose, another eye-color mutant in linkage group I, exhibit a third new phenotype, yellow-orange eye.

Animals↗
PubMedDate not supplied

Male determining factor on chromosome 3 in the mosquito, Culex tritaeniorhynchus.

Recent experiments indicate that the sex allele M in different populations of Culex tritaeniorhynchus may be present in different linkage groups. In some laboratory wild-type and mutant stocks, M was found to be unlinked to the mutants of linkage group I. Further experiments have demonstrated that in these stocks M is linked to the mutants in linkage group III. Thus, M may be associated with either linkage group I or III. All other markers within a linkage group appear to remain linked to each other and the recombination frequencies among linked markers remain unaltered irrespective of whether or not the M allele was present. The females behave as the homogametic sex in crosses with both types of males. The M allele when associated with linkage group I has been designated M1, when associated with linkage group III it is designated M3. The gene order when M3 is present in linkage group III is Lp-M3-Adh-bw-ae.

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PubMedDate not supplied

Translocations in the mosquito, Culex tritaeniorhynchus.

Fifty-eight translocations were produced and studied using improved genetic and cytogenetic techniques now available for Culex tritaeniorhynchus. Data confirm previous chromosome-linkage correlation studies and indicated that the e locus is on the long arm (2R) of chromosome 2.

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PubMedDate not supplied

Genetic analysis of two enzyme polymorphisms in a malaria vector mosquito: octanol dehydrogenase and acid phosphatase in Anopheles culicifacies Giles.

Genetic analysis was performed on two polymorphic enzyme systems in the malaria vector, Anopheles culicifacies Giles. The data indicate that both enzymes, octanol dehydrogenase and acid phosphatase, are controlled by autosomal loci but that these two loci are not linked. The three expected linkage groups in this mosquito have now been identified: linkage group I contains sex and rose-eye; linkage group II contains Odh; and linkage group III contains Acph.

Acid Phosphatase↗
PubMedDate not supplied

An EMS-induced mutant, rose eye, in Culex quinquefasciatus.

The genetic analysis of an EMS-induced, recessive, sex-linked eye mutant, rose eye (re), is presented. This locus is closely linked to maroon eye (approximately four map units apart). Individuals homozygous for both rose- and maroon-eye exhibit a third phenotype, white to pale pink eyes.

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PubMedDate not supplied

A phosphoglucomutase polymorphism in the mosquito, Anopheles culicifacies.

A survey of phosphoglucomutase (Pgm) among laboratory strains of Anopheles culicifacies has uncovered two electrophoretic variants. Detailed genetic analysis revealed that these variants are inherited as codominant alleles at a single locus. The Pgm locus has been assigned to linkage group III approximately 39 map units from Acph (acid phosphatase) and 8.5 map units from Dl (dieldrin resistance). The data indicate that the probable gene sequence is Acph-Dl-Pgm.

Acid Phosphatase↗
PubMedDate not supplied

Genetic sexing for a mosquito sterile-male release.

Two strains of Anopheles culicifacies have been synthesized in which the dieldrin resistance locus on chromosome 3 has been translocated to the Y chromosome. Both strains appear sufficiently stable for the preferential recovery of males for mass production of mosquitoes for field releases.

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PubMedDate not supplied

Esterases in the malaria vector mosquito, Anopheles culicifacies. Genetic and linkage analyses of an alpha and beta polymorphism.

The genetic and linkage analyses of an alpha and beta esterase polymorphism in Anopheles culicifacies are presented. A survey of laboratory strains uncovered four electrophoretic variants for the alpha esterase and two for the beta esterase. Genetic analyses indicated that the variants of the alpha esterase are under the control of codominant alleles of a single locus and that this locus is linked to the locus controlling the expression of the codominant alleles of the beta esterases. The esterases are not linked either to sex (chromosome 1) or to maroon eye (chromosome 2) but to the chromosome 3 markers, dieldrin resistance and phosphoglucomutase. The gene sequence is Est-alpha--Dl--Pgm--Est-beta dnd the recombination frequencies are as follows: Est-alpha--Dl = 2.9 percent; Dl--Pgm = 5.8 percent; Pgm--Est-beta = 6.4 percent; Est-alpha--Est-beta = 15.1 percent, Est-alpha--Pgm = 8.7 percent and Dl--Est-beta = 12.2 percent.

Animals↗
PubMedDate not supplied

Linkage group III in the malaria vector, Anopheles stephensi.

The linkage relationships among four loci in linkage group III of Anopheles stephensi Liston have been investigated. The data indicate that the sequence is sp-dp-Bl-Dl, and the observed recombination frequencies are as follows: sp-dp = 35.88 percent, dp-Bl = 19.48 percent, Bl-Dl = 21.77 percent, and sp-Dl = 77.13 percent.

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PubMedDate not supplied

Induced chromosomal aberrations and linkage group-chromosome correlation in Anopheles stephensi.

Genetic and cytogenetic investigations of 14 strains of Anopheles stephensi with induced chromosomal aberrations have resulted in the assignment of the three linkage groups to their respective chromosomes. In addition, the correlation between the ovarian polytene chromosomes and the mitotic chromosomes was demonstrated. Indirect evidence for the presence of heterochromatic segments in the chromosomal complement was found.

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