Related Experiment Video
Updated: Jun 22, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila
Published on: August 22, 2013
[Molecular variability of testes-specific betaNACtes genes in Drosophila melanogaster genome]
Abstract:
Family of betaNACtes genes in the Drosophila melanogaster genome is a model to investigate the mechanisms of molecular evolution of recently evolved genes. The betaNACtes genes encode proteins, homologous to beta subunit of nascent polypeptide-associated complex (NAC), are expressed in testes and localized on the X chromosome as two two-gene clusters and one separate copy. We collected population polymorphism data for betaNACtes genes using several wild-type stocks of D. melanogaster and compared betaNACtes paralogs with each other. We have shown heterogeneous pattern of betaNACtes genes polymorphism: genes in 3' region of two-gene clusters are low polymorphic, whereas separate betaNACtesl gene is most variable. 5'betaNACtes copies in two-gene tandems are practically identical, whereas 3'betaNACtes copies are highly diverged. Thus, we propose local gene conversion providing selective homogenization of 5'genes. Comparison of betaNACtes paralogs has shown that majority of amino acid differences are in N-terminal part of proteins, containing betaNAC domain. McDonald-Kreitman test of betaNACtes paralog divergence shows the involvement of positive selection in the course of betaNACtes gene family evolution.
Related Concept Videos
Genetic Variation
Genes exist in different versions called alleles, which...
Position-effect Variegation
The Ratio of X Chromosome to Autosomes
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Background and Environment Affect Phenotype
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Genetic Screens
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes...

