The pathology of embryo death caused by the male-killing Spiroplasma bacterium in Drosophila nebulosa.
BACKGROUND
Inherited bacteria that kill male offspring, male-killers, are known to be common in insects, but little is understood about the mechanisms used by male-killing bacteria to kill males. In this paper we describe the tempo and changes that occur during male-killing by Spiroplasma bacteria in the host Drosophila nebulosa.


RESULTS
Spiroplasma infected D. nebulosa males were developmentally retarded from 6-8 h into embryonic development at 25 degrees C, and arrested at between stages 12 and 13 of embryogenesis (10-12 h). Dying males were characterized by a failure to form segments, and ultimately disintegration of the normal oval embryonic shape. Prior to death, dying males exhibited widespread apoptosis, as testified by TUNEL staining.


CONCLUSIONS
The Spiroplasma kills male Drosophila in a narrow developmental period, shortly after the formation of the host dosage compensation complex that is required for male-killing. Male death is preceded by widespread apoptosis, but it is uncertain if this is primary or secondary apoptosis.
Bentley
Joanna K
JK
Department of Biology, University College London, 4 Stephenson Way, London NW1 2HE, UK. joanna.bentley@fco.gov.uk
Veneti
Zoe
Z
Heraty
Joseph
J
Hurst
Gregory D D
GD
D000367:Age Factors; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D004330:Drosophila / Q000196:embryology / Q000382:microbiology*; D004625:Embryo, Nonmammalian / Q000473:pathology*; D020287:In Situ Nick-End Labeling; D008297:Male; D012737:Sex Factors; D013149:Spiroplasma