Short Communication |
Corresponding author: Vladimir E. Gokhman ( vegokhman@hotmail.com ) Academic editor: Petr Janšta
© 2019 Vladimir E. Gokhman, Francesco Nugnes, Umberto Bernardo.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Gokhman VE, Nugnes F, Bernardo U (2019) Chromosomes of Eupristina verticillata Waterston, 1921 and an overview of known karyotypes of chalcid wasps of the family Agaonidae (Hymenoptera). Journal of Hymenoptera Research 71: 157-161. https://doi.org/10.3897/jhr.71.35951
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The karyotype of Eupristina verticillata Waterston, 1921 (Agaonidae) from Italy was studied for the first time using chromosome morphometrics. The present study showed that this species has n = 6 and 2n = 12, with five larger metacentrics and a smaller acrocentric chromosome in the haploid set. A brief overview of known karyotypes of chalcid wasps of the Agaonidae is given; certain features of karyotype evolution of this family are discussed.
Chalcidoidea, Agaonidae, chromosomes, karyotypes
Chalcidoidea are one of the most speciose, taxonomically complicated and economically important groups of parasitoid Hymenoptera (
Green syconia of Ficus microcarpa Linnaeus, 1782 (Moraceae) containing immature stages of E. verticillata were collected by the senior author in July 2018 in the Villa Comunale (city park) of Napoli, Italy (40°49'58.4"N 14°14'3"E). Immediately after collection, the syconia were dissected in the lab, and wasp prepupae were extracted from the galls.
Chromosomal preparations were obtained from cerebral ganglia of prepupae of E. verticillata generally following the protocol developed by
Metaphase plates were analyzed under a Zeiss Axioskop 40 FL epifluorescence microscope (Carl Zeiss, Göttingen, Germany). Images of chromosomes were taken with Zeiss AxioCam MRc digital camera using Zeiss AxioVision software version 3.1. To prepare illustrations, the resulting images were arranged and enhanced with Adobe Photoshop 8.0. KaryoType version 2.0 software was also used for taking measurements from four diploid metaphase plates of E. verticillata having well-defined chromosome morphology. For each chromosome of the haploid set, we report both its relative length (100 × length of the chromosome divided by total length of the set) and centromeric index (100 × length of the shorter arm divided by total length of the chromosome). The chromosomes were classified into metacentrics (M), subtelocentrics (ST) and acrocentrics (A) following guidelines provided by
The diploid karyotype of E. verticillata contains the largest pair of metacentric chromosomes, two pairs of shorter metacentrics, two other pairs of considerably smaller metacentric chromosomes, and the shortest pair of acrocentrics (Fig.
Relative lengths (RL) and centromeric indices (CI) of chromosomes of E. verticillata (mean ± SD).
Chr. no. | RL | CI |
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1 | 23.30 ± 1.35 | 42.38 ± 3.97 |
2 | 21.00 ± 0.77 | 44.53 ± 3.15 |
3 | 20.64 ± 0.76 | 43.11 ± 5.28 |
4 | 15.63 ± 0.31 | 46.72 ± 2.71 |
5 | 11.51 ± 0.78 | 46.21 ± 2.82 |
6 | 7.92 ± 0.46 | 0 |
The karyotype of E. verticillata is structurally similar to that of the only known member of the family Agaonidae with the same chromosome number (Table
Species | 2n | Chromosome formula | Reference |
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Blastophaga psenes (Linnaeus, 1758) | 12 | 10M + 2ST |
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Ceratosolen emarginatus Mayr, 1916 | 10 | 10M |
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C. gravelyi Grandi, 1916 | 10 | 10M |
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C. solmsi (Mayr, 1885) | 10 | 10M |
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Eupristina altissima Balakrishnan & Abdurahiman, 1981 | 10 | 10M |
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E. verticillata Waterston, 1921 | 12 | 10M + 2A | Present study |
Eupristina sp. | 10 | 10M |
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The present study was partly supported by a research grant no. 18-04-00611 from the Russian Foundation for Basic Research to VEG.