Karyotype, sex chromatin and sex chromosome differentiation in the carob moth,Ectomyelois ceratoniae(Lepidoptera: Pyralidae)
Open Access
- 1 January 2004
- journal article
- research article
- Published by Firenze University Press in Caryologia
- Vol. 57 (2), 184-194
- https://doi.org/10.1080/00087114.2004.10589391
Abstract
This paper reports results of the first cytogenetic investigation carried out in the carob moth, Ectomyelois ceratoniae Zeller, the serious polyphagous pest of both stored products and field crops in the Mediterranean basin and Near East regions. Preparations of mitotically dividing spermatogonia and oogonia revealed that the carob moth karyotype consists of 2n = 62 chromosomes. As typical for Lepidoptera, the chromosomes were of a holokinetic type, only slightly differed in their sizes, and displayed no morphological structures including primary constrictions (the centromeres) that could enable us their identification. Metaphase I spermatocytes showed 31 bivalents. Accordingly, 31 chromosome elements were observed in metaphase II spermatocytes. Hence the haploid chromosome number is n = 31. In pachytene complements, two NOR bivalents were observed. In highly polyploid nuclei of the Malpighian tubule cells and silk glands, females showed a heterochromatin body, the so-called sex chromatin or W chromatin, that was absent in male nuclei. This indicated that the carob moth possesses a WZ/ZZ sex chromosome system. However, we failed to identify the sex chromosome bivalent WZ in pachytene oocytes. In order to differentiate the sex chromosomes, we employed genomic in situ hybridization (GISH) and comparative genomic hybridization (CGH). GISH detected the W chromosome by strong binding of the Cy3-labelled, female-derived DNA probe. With CGH, both the Cy3-labelled female-derived probe and Fluor-X labelled male-derived probe evenly bound to the W. This suggested that the W is composed predominantly of repetitive DNA sequences occurring scattered in other chromosomes but accumulated in the W chromosome.Keywords
This publication has 28 references indexed in Scilit:
- Applications of F 1 Sterility for Research and Management of Cactoblastis cactorum (Lepidoptera: Pyralidae)The Florida Entomologist, 2001
- Season-Long Releases of Partially Sterile Males for Control of Codling Moth (Lepidoptera: Tortricidae) in Washington ApplesEnvironmental Entomology, 2001
- Sex chromatin and sex chromosome systems in nonditrysian Lepidoptera (Insecta)Journal of Zoological Systematics and Evolutionary Research, 2000
- Inherited Effects in F1 Progeny of Partially Sterile Male Phthorimaea operculella (Lepidoptera: Gelechiidae)Journal of Economic Entomology, 1997
- Synaptonemal complexes in female and male meiotic prophase of Ephestia kuehniella (Lepidoptera)Heredity, 1993
- Genetic control of pest Lepidoptera: construction of a balanced lethal strain in Ephestia kuehniellaEntomologia Experimentalis et Applicata, 1991
- Identification of the Z-W bivalent in the silkworm, Bombyx moriGenetica, 1991
- Genetic control of the pest lepidoptera: Gamma-ray induction of translocations between sex chromosomes of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)Journal of Stored Products Research, 1990
- Karyotype and achiasmatic female meiosis in Helicoverpa armigera (Hübner) and H. punctigera (Wallengren) (Lepidoptera: Noctuidae)Genome, 1989
- “Ringer”, solutions and some notes on the physiological basis of their ionic compositionComparative Biochemistry and Physiology, 1961