Estimation of population fitness of parental races Drosophila nasuta nasuta and Drosophila nasuta albomicana and of the newly evolved Cytoraces I and II

Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 58-62 ◽  
Author(s):  
N. B. Ramachandra ◽  
H. A. Ranganath
Keyword(s):  
Rate Of Development ◽  
Genetic Systems ◽  
Drosophila Nasuta ◽  
Drosophila Nasuta Nasuta ◽  
Adult Rate ◽  
Population Fitness

Interracial hybridization between Drosophila nasuta nasuta (2n = 8) and Drosophila nasuta albomicana (2n = 6) has resulted in the emergence of new karyotypic strains called Cytorace I (♀ 2n = 7; ♂ 2n = 6) and Cytorace II (♀ and ♂ 2n = 6). The parental and the newly evolved Cytoraces were assessed for parameters of fitness, i.e., fecundity, egg to adult rate of development, egg to adult viability, and adaptedness. The newly evolved Cytoraces not only differ from each other but also differ from their parental races in their fitness phenotypes. Each one of these four strains represent features of different genetic systems with different adaptive phenotypes.Key words: Drosophila, interracial hybridization, population fitness.

scholarly journals Adaptation to larval crowding in Drosophila ananassae and Drosophila nasuta nasuta: increased larval competitive ability without increased larval feeding rate

2016 ◽  
Vol 95 (2) ◽  
pp. 411-425 ◽  
Author(s):  
ARCHANA NAGARAJAN ◽  
SHARMILA BHARATHI NATARAJAN ◽  
MOHAN JAYARAM ◽  
ANANDA THAMMANNA ◽  
SUDARSHAN CHARI ◽  
...  
Keyword(s):  
Competitive Ability ◽  
Feeding Rate ◽  
Drosophila Ananassae ◽  
Larval Feeding ◽  
Larval Crowding ◽  
Drosophila Nasuta ◽  
Drosophila Nasuta Nasuta

scholarly journals POPULATION GENETICS OF DROSOPHILA NASUTA NASUTA, DROSOPHILA NASUTA ALBOMICANA AND THEIR HYBRIDS. I. KARYOTYPIC MOSAICISM IN THE HYBRID POPULATIONS

Genetics ◽  
1979 ◽  
Vol 93 (1) ◽  
pp. 211-215
Author(s):  
M R Rajasekarasetty ◽  
L Siddaveere Gowda ◽  
N B Krishnamurthy ◽  
H A Ranganath
Keyword(s):  
Population Genetics ◽  
Chromosomal Races ◽  
Drosophila Nasuta ◽  
Drosophila Nasuta Nasuta

ABSTRACT D. n. nasuta and D. n. albomicana constitute a pair of chromosomal races with 2n=8 and 2n=6, respectively. The F1 of these has 2n=7 and it is fertile. There exists a state of karyotypic mosaicism as evidenced by the presence of 26 types of chromosome combinations in F2, F3, and F10 populations. In the midst of this karyotypic noise, the karyotype similar to that of F1 reached 51% of the population. Implications of these findings are discussed.

Autoradiographic study of transcription and dosage compensation in the sex and neo-sex chromosome of Drosophila nasuta nasuta and Drosophila nasuta albomicans

Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 71-78 ◽  
Author(s):  
G Mahesh ◽  
N B Ramachandra ◽  
H A Ranganath
Keyword(s):  
X Chromosome ◽  
Dosage Compensation ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Autoradiographic Study ◽  
The Other ◽  
Chromosomal Races ◽  
Heteromorphic Sex Chromosomes ◽  
Drosophila Nasuta ◽  
Drosophila Nasuta Nasuta

Cellular autoradiography is used to study the transcription patterns of the polytene X chromosomes in Drosophila nasuta nasuta and D. n. albomicans. D. n. nasuta, with 2n = 8, includes a pair of complete heteromorphic sex chromosomes, whereas D. n. albomicans, with 2n = 6, has a pair of metacentric neo-sex chromosomes representing incomplete heteromorphic sex chromosomes. The neo-X chromosome has two euchromatic arms, one representing the ancestral X while the other represents the ancestral autosome 3 chromosomes. The metacentric neo-Y chromosome has one arm with a complete heterochromatic ancestral Y and the other arm with a euchromatic ancestral autosome 3. The transcription study has revealed that the X chromosome in D. n. nasuta is hyperactive, suggesting complete dosage compensation, while in the neo-X chromosome of D. n. albomicans the ancestral X chromosome is hyperactive and the ancestral autosome 3, which is part of the neo-sex chromosome, is similar to any other autosomes. This finding shows dosage compensation on one arm (XLx/–) of the neo-X chromosome, while the other arm (XR3/YR3) is not dosage compensated and has yet to acquire the dosage compensatory mechanism.Key words: Drosophila, chromosomal races, neo-sex chromosome, transcription and dosage compensation.

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