Mean total ovariole numbers were calculated for twenty-six wild-type strains of Drosophila melanogaster of global origin.These diverse strains of Drosophila melanogaster varied greatly as to their calculated mean ovariole numbers. The estimated right-left correlation coefficients were found to be as diverse as the calculated mean ovariole numbers and; therefore, indicated genetic heterogeneity varied among the strains.During the course of this investigation, a particular strain was found to exhibit an innate propensity for expressing rudimentary ovaries and testes, both unilaterally and bilaterally.Unilateral females with a greatly reduced functional ovariole number demonstrated a compensating increase in mean pre-yolky egg chambers or only germarial mesoderm dispersed of at eggs produced per day per ovariole. Unilaterally rudimentary testes in males of-this strain resulted in decreased mean egg production per day per ovariole in females to which they were mated.Mean hatchability was reduced if either the male or the female had unilaterally rudimentary gonads, but was not reduced further by having both male and female unilateral in a single pair mating. It is suggested that hatchability may be reduced in unilaterally rudimentary females because the reduced maturation time (increased rate of oogenesis) resulted in defective eggs.Serial cross-section analysis of rudimentary ovaries indicated that some pole cells (primordial germ cells) may have been incorporated into the larval gonad. Cellular debris, which may have been degenerating aberrant germaria, and collected posteriorly in rudimentary ovarioles.Increasing larval density increased the incidence rudimentary gonads only when their oogenesis had occurred 25°C. Oogenesis at 29°C almost completely suppressed the expression of rudimentary gonads.Maternal effects were evident but only if the progeny's oogenesis occurred at 25°C and their embryogenesis and larval instars at 29°C.
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/180703 |
| Date | January 1973 |
| Creators | Pappas, Nick, |
| Contributors | Engstrom, Lee E. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | v, 74 leaves : ill. ; 28 cm. |
| Source | Virtual Press |
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