Frederick Jay Gottlieb

A cytoplasmic symbiont in Ephestia( = Anagasta) kuehniella: Location and morphology

Abstract Numerous mycoplasmalike inclusions were found to be present within cells of the larval and adult testis sheath of wild-type Ephestia kuehniella . These pleomorphic bodies are isolated from the sheath cell cytoplasm in membrane-bound vacuoles. Cytologically, they resemble Mycoplasma hominis and the mycoplasmalike symbiont associated with sterility in Drosophila paulistorum . No sterility or other pathology is noted in infested Ephestia .

Interorder transfer of mycoplasma-like microorganisms between Drosophila paulistorum and Ephestia kuehniella: Tissues, dosages, and effects

Abstract Testis and head extracts of sterile male intersemispecific hybrid Drosophila paulistorum are pathogenic when injected into Ephestia kuehniella larvae. The time and frequency of death of the recipients is a function of the extract concentration. Extracts of Ephestia recipients are pathogenic and will kill E. kuehniella larvae and D. paulistorum adults. Larval Drosophila recipients of these extracts survive through pupation. A majority of these recipients fail to eclose. Those animals which do survive to the adult stage and which are fertile demonstrate the same pattern of sterility among their progeny as is found in D. paulistorum hybrids and recipients of D. paulistorum extracts. The results indicate that the pathogenicity of the extracts is due to the mycoplasma-like microorganisms which are responsible for the male intersemispecific hybrid sterility in D. paulistorum . The mycoplasma-like microorganisms grow rapidly in E. kuehniella hosts, with a division time of approximately 1.8 hr, and they retain their host specificity for the semispecies of D. paulistorum .

Reproductive Isolation in a Neotropical Insect: Behavior and Microbiology

The Drosophila paulistorum Dobzhansky & Pavan complex offers an excellent opportunity for the study of the relationship between an insect host and its microbial symbiont. Electron microscopy reveals that all members of this insect group harbor endosymbionts which, by all appearances, are cell-wall deficient organisms (CWD). While it is not known if the CWDs of D. paulistorum are essential to their hosts, it is clear that a stable, benign relationship exists between the host and its own CWD. However, our evidence indicates that transfer of an endosymbiont from one semispecies of D. paulistorum to another semispecies results in male sterility. The specificity exhibited by the endosymbionts increases reproductive isolation between semispecies and may have contributed to the evolutionary and taxonomic complexity of D. paulistorum as a widespread superspecies.

Control of oocyte production, development, and release inDrosophila melanogaster

SummarySterility in the Hairy-wing 49c mutant ofDrosophila melanogaster is due to the failure of mature oocytes to pass from the oviduct into the uterus.Patterns of oocyte accumulation in the ovaries, oviducts and uterus of mutant and wild-type flies indicate that ovulation is initiated first by mating and thereafter by the absence of an oocyte in the uterus. While oocyte production is also stimulated by mating, it is maintained by a low number of oocytes in the ovary.Mating also appears to initiate events which cause mature oocytes to deteriorate if they are not soon oviposited.

A unique cause of female sterility inDrosophila melanogaster

SummaryHistological studies do not permit the distinction between an oocyte, ovary or oviduct malformation as the primary cause of sterility in females homozygous for the Hairywing 49c allele inDrosophila melanogaster. Reciprocal transplantations of larval ovaries between homozygous mutant larvae and normal larvae demonstrate that the sterility is due to a malfunctioning of the oviduct, presumably at the junction of the common oviduct and the uterus. This failure of the oviduct to function normally appears to represent a unique cause of female sterility in this organism.

Anthracene-induced melanotic tumors in Drosophila☆

Abstract A significant increase in the formation of melanotic tumor (nonneoplastic, melanized hemocytic aggregates) was observed among first- and second-generation progeny of Drosophila melanogaster males and females which had been exposed chronically as larvae to low concentrations of anthracene. Results are consistent with the interpretation that anthracene, solubilized with detergents, induces autosomal dominant melanotic tumor mutations which have low penetrance.

Interorder transfer of mycoplasmalike microorganisms betweenDrosophila paulistorum andEphestia kühniella. II. Numbers of MLO and sterility

A successful attempt was made to culture the mycoplasmalike microorganism causing semispecific hybrid male sterility inDrosophila paulistorum utilizingEphestia kühniella as the intermediate host. Data gleaned from this passage indicates that the induction of sterility depends upon the quality not the quantity of infectious intracellular symbionts.

Pupal respiratory complex of Tanypus carinatus Sublette var. (Diptera: Chironomidae)

Abstract The thoracic respiratory organ of the pupa of the genus Tanypus is usually assumed to lack a plastron element. Little information has appealed in the literature regarding the active site(s) of respiration. However, it has been inferred that the aeropyle-like structure at the tip of the organ serves in that role. Detailed examination of Tanypus carinatus Sublette var. respiratory organs by means of the scanning electron microscope, transmission electron microscope, and light microscope indicates the presence of a respiratory complex, whose elements bear structural similarities to those of plastrons, and which covers the entire surface of the respiratory organ. The subsurface meshwork, which previously has been interpreted as only supportive in function, is shown to be tubular, and appears to be intimately connected with the plastron-like surface elements. Functional and evolutionary implications of this plastron-like arrangement are discussed.