Though the 9þ2 axonemal organization has generally been conserved throughout metazoan evolution, insect spermatozoa possess a substantial variety in axoneme ultrastructure, displaying different axonemal patterns. Therefore, insects provide a wide range of models that may be useful for the study of the mechanisms of axoneme assembly. We have used antibodies specific for glutamylated, monoglycylated, and polyglycylated tubulin to investigate the tubulin isoform content expressed in the unorthodox sperm axonemes of four insect species belonging to both of the superorders Palaeoptera and Neoptera. Each one of these axonemal models exhibits distinctive structural features, either showing the typical radial organization endowed with a ninefold symmetry or consisting of an helical arrangement with up to 200 microtubular doublets, but in all cases these axonemes share the absence of a microtubule central pair. Our results showed that all these atypical patterns are characterized by a dramatic decrease in both tubulin glycylation and glutamylation levels or even lack of both polymodifications. These data provide the first examples of a simultaneous extreme reduction or even absence of both polymodifications in axonemal tubulin. Given the unrelated positions of the analyzed species in the insect phylogenetic tree, this common feature is probably not due to evolutionary relationships. Therefore, our findings support the hypothesis of the existence of a correlation between the low level of polymodifications and the lack of a microtubule central pair in these peculiar insect flagellar axonemes, similarly as was previously proposed for cilia of Tetrahymena glycylation site mutants.

Mencarelli, C., Caroti, D., Bré, M., Levilliers, N., Dallai, R. (2005). Tubulin glycylation and glutamylation deficiencies in unconventional insect axonemes. CELL MOTILITY AND THE CYTOSKELETON, 61(4), 226-236 [10.1002/cm.20081].

Tubulin glycylation and glutamylation deficiencies in unconventional insect axonemes

Mencarelli, Caterina;
2005-01-01

Abstract

Though the 9þ2 axonemal organization has generally been conserved throughout metazoan evolution, insect spermatozoa possess a substantial variety in axoneme ultrastructure, displaying different axonemal patterns. Therefore, insects provide a wide range of models that may be useful for the study of the mechanisms of axoneme assembly. We have used antibodies specific for glutamylated, monoglycylated, and polyglycylated tubulin to investigate the tubulin isoform content expressed in the unorthodox sperm axonemes of four insect species belonging to both of the superorders Palaeoptera and Neoptera. Each one of these axonemal models exhibits distinctive structural features, either showing the typical radial organization endowed with a ninefold symmetry or consisting of an helical arrangement with up to 200 microtubular doublets, but in all cases these axonemes share the absence of a microtubule central pair. Our results showed that all these atypical patterns are characterized by a dramatic decrease in both tubulin glycylation and glutamylation levels or even lack of both polymodifications. These data provide the first examples of a simultaneous extreme reduction or even absence of both polymodifications in axonemal tubulin. Given the unrelated positions of the analyzed species in the insect phylogenetic tree, this common feature is probably not due to evolutionary relationships. Therefore, our findings support the hypothesis of the existence of a correlation between the low level of polymodifications and the lack of a microtubule central pair in these peculiar insect flagellar axonemes, similarly as was previously proposed for cilia of Tetrahymena glycylation site mutants.
2005
Mencarelli, C., Caroti, D., Bré, M., Levilliers, N., Dallai, R. (2005). Tubulin glycylation and glutamylation deficiencies in unconventional insect axonemes. CELL MOTILITY AND THE CYTOSKELETON, 61(4), 226-236 [10.1002/cm.20081].
File in questo prodotto:
File Dimensione Formato  
Mencarelli et al 2005.pdf

non disponibili

Tipologia: Post-print
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 316.04 kB
Formato Adobe PDF
316.04 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/26688
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo