Projections of male-specific receptor neurons in the antennal lobe of the oriental tobacco budworm moth,Helicoverpa assulta: A unique glomerular organization among related species

2005 ◽  
Vol 486 (3) ◽  
pp. 209-220 ◽  
Author(s):  
Bente G. Berg ◽  
Tor J�rgen Almaas ◽  
Jan G. Bjaalie ◽  
Hanna Mustaparta
Keyword(s):  
Related Species ◽  
Antennal Lobe ◽  
Tobacco Budworm ◽  
Specific Receptor ◽  
Helicoverpa Assulta ◽  
Receptor Neurons ◽  
Male Specific

Effects of the sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta (Lepidoptera, Noctuidae)

2001 ◽  
Vol 204 (22) ◽  
pp. 3935-3942 ◽  
Author(s):  
Seong Eun Jeong ◽  
Yun Lee ◽  
Jeong Hee Hwang ◽  
Douglas C. Knipple
Keyword(s):  
Male Fertility ◽  
Chemical Constituents ◽  
Direct Injection ◽  
Arginine Decarboxylase ◽  
Tobacco Budworm ◽  
Polyamine Metabolism ◽  
Helicoverpa Assulta ◽  
Continuous Feeding ◽  
The Common ◽  
Lepidoptera Noctuidae

SUMMARY We investigated the effects of sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta. We found that continuous feeding of oleander sap during the larval period significantly affects fertility in males but not in females. This effect was also induced by direct injection of oleander sap into the hemocoel of 2-day-old pupae. Histological analyses of developing testes following oleander injection revealed a developmental delay and progressively more severe morphological abnormalities in the later stages of development. The effects of oleander sap on spermatogenesis in H. assulta were associated with greatly reduced levels of the two major polyamines, spermidine and spermine, in testis compared with saline-injected controls. In contrast, levels of putrescine, which is a precursor of both spermidine and spermine, and the activities of the enzymes ornithine decarboxylase and arginine decarboxylase, which are involved in the biosynthesis of putrescine, were initially elevated following oleander injection, but subsequently failed to undergo the induction that normally occurs during late pupal development. The effects of oleander sap on spermidine and spermine levels could be the result of direct inhibition by chemical constituents of the oleander sap of one of the enzymes used in common in the conversions of putrescine to spermidine and spermidine to spermine; alternatively, these effects on polyamine metabolism could be secondary to the disruption of a more fundamental process in the developmental program guiding spermatogenesis in H. assulta.

Antennal Lobe Processing Increases Separability of Odor Mixture Representations in the Honeybee

2010 ◽  
Vol 103 (4) ◽  
pp. 2185-2194 ◽  
Author(s):  
Nina Deisig ◽  
Martin Giurfa ◽  
Jean Christophe Sandoz
Keyword(s):  
Antennal Lobe ◽  
Second Order ◽  
Insect Brain ◽  
Output Level ◽  
Local Networks ◽  
Odor Mixture ◽  
Receptor Neurons ◽  
Evoked Activity ◽  
Input Level ◽  
Olfactory Space

Local networks within the primary olfactory centers reformat odor representations from olfactory receptor neurons to second-order neurons. By studying the rules underlying mixture representation at the input to the antennal lobe (AL), the primary olfactory center of the insect brain, we recently found that mixture representation follows a strict elemental rule in honeybees: the more a component activates the AL when presented alone, the more it is represented in a mixture. We now studied mixture representation at the output of the AL by imaging a population of second-order neurons, which convey AL processed odor information to higher brain centers. We systematically measured odor-evoked activity in 22 identified glomeruli in response to four single odorants and all their possible binary, ternary and quaternary mixtures. By comparing input and output responses, we determined how the AL network reformats mixture representation and what advantage this confers for odor discrimination. We show that increased inhibition within the AL leads to more synthetic, less elemental, mixture representation at the output level than that at the input level. As a result, mixture representations become more separable in the olfactory space, thus allowing better differentiation among floral blends in nature.

scholarly journals Evolutionary characterization of a Y chromosomal sequence conserved in the genus Mus

1988 ◽  
Vol 52 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Yutaka Nishioka
Keyword(s):  
Related Species ◽  
Rattus Norvegicus ◽  
Phylogenetic Relationships ◽  
Repetitive Sequence ◽  
Repetitive Sequences ◽  
Closely Related Species ◽  
Specific Hybridization ◽  
Male Specific ◽  
Chromosomal Sequence

SummaryThe extent of accumulation of mouse Y chromosomal repetitive sequences generally correlates with the known phylogenetic relationships in the genus Mus. However, we describe here a M. musculus Y chromosomal repetitive sequence, designated as ACClfl, whose accumulation patterns among eight Mus species do not correspond to their phylogenetic relationships. Although male-specific hybridization bands were present in all the species examined, significant accumulation (> 200 copies) in the Y chromosomes was found in M. minutoides (subgenus Nannomys), M. pahari (subgenus Coelomys) and M. saxicola (subgenus Pyromys) as well as in the three closely related species M. hortulanus, M. musculus and M. spretus that belong to the subgenus Mus. Unexpectedly, the Y chromosomes of M. caroli and M. cookii (both subgenus Mus) had considerably reduced amounts of ACClfl-related sequences. Furthermore, in rats (Rattus norvegicus) the major accumulation sites appear to be autosomal. These observations suggest that caution must be taken in the interpretation of data obtained with repetitive sequences that have evolved quickly.

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