0000000000113724
AUTHOR
E. Catalano
Chromosome analysis of Bothus podas (Pisces, Pleuronectiformes) from the Mediterranean Sea
A modal diploid number 2n=38 has been determined in both sexes of the pleuronectiform Bothus podas from the Gulf of Palermo (Mediterranean). An XX-XY sex-determining mechanism presumably occurs in this species. Application of silver staining (NORs) along with G- and C-banding techniques showed that secondary constrictions occurring in a large metacentric pair were variable in length in different fish. Polymorphisms of these areas seem to have a genetic, rather than transcriptional, basis.
Karyological studies in Coris julis (Pisces, Labridae).
In the present investigation the diploid number 2n = 48 (NF = 58) has been determined for females, primary males, and secondary males of Coris julis from the Gulf of Palermo. Differentiated sex chromosomes have not been observed in the population under study.
Abnormal peripheral and central visual processing in migraine
Sound induced flash illusion (SIFI) is an illusory cross modal (audio-visual) phenomenon critically dependent upon excitability of visual cortex. A recent study with SIFI confirmed hyperexcitability of visual cortex in migraine; patients with migraine show abnormality of chromatic perception. Here we explored the relationship between peripheral chromatic and central visual dysfunction in patients with migraine
A male XO sex-determining mechanism in Theodoxus meridionalis (Neritidae) (Prosobranchia, Archaeogastropoda).
The haploid number of chromosomes n=12+h and the diploid values 2n=25 in males, and 2n=26 in females, have been determined for three geographically separated populations of Theodoxus meridionalis (Neritidae). A male XO sex-determining mechanism has been observed for this species.
Spermatocyte chromosome alterations intruncatella subcylindrica (L., 1767) (Mollusca, Mesogastropoda) following exposure to dibutyltin(IV) and tributyltin(IV) chlorides
In order to analyze chromosomes for possible numerical and structural alterations in response to exposure to organotin(IV) compounds, gastropod Truncatella subcylindrica specimens were treated with dibutyltin(IV) and tributyltin(IV) chloride solutions with different exposure times. Experimental evidence suggests that tributyltin(IV) chloride is more toxic to this organism than dibutyltin(IV) dichloride at low concentrations. Furthermore, the toxicity responses to these organotin(IV) derivatives seem to be proportional to both concentration and exposure time. The following structural lesions have been identified by comparative analysis of spermatocyte chromosomes from untreated specimens and…
Spermatocyte chromosome analysis of Helicella virgata (Pulmonata: Helicidae): silver-stained and C-banded chromosomes.
Chromosome numbers of the snail Helicella virgata from the fields of Castellammare del Golfo (Sicily) are n = 26 and 2n = 52. Silver-staining analyses of testicular cells suggest that both mitotic and meiotic chromosomes are involved in nucleolus organization. A within-individual variability in NOR-banding pattern is present in each of the 20 specimens analyzed.
Spermatocyte chromosome banding studies inBuccinulum corneum (Prosobranchia: Neogastropoda): Variation in silver-NOR banding pattern
Diploid number (2n=72), and haploid number (n=36) forBuccinulum corneum (L. 1758) collected from the Gulf of Palermo in December 1987 were determined. A simple method to obtain nucleolar organizer regions (NOR), and constitutive heterochromatin regions (C-bands) of chromosomes ofB. corneum is described. Analyses of silver-stained chromosome preparations ofB. corneum suggest that a within-individual variability in NOR-banding pattern is present in each of the five specimens analysed.
Chromosomes of the Parasitic Isopod Anilocra Physodes
AbstractCounts of mitotic chromosomes have allowed to determine 2n = 12 as the modal diploid number of Anilocra physodes. Application of the C-banding technique reveals that two hetero-chromatic blocks bordering the centromeric region occur in each chromosome. This supports the notion that the actual low chromosome number of A. physodes may have been derived through a process of Robertsonian fusion.
Chromosomal polymorphism associated with Robertsonian fusion in Seriola dumerili (Risso, 1810) (Pisces: Carangidae)
The diploid numbers 2n= 48, and 2n= 47 have been determined for the greater amberjack, Seriola dumerili. A chromosome polymorphism due to Robertsonian fusion is present in this species. A simple sex-determining mechanism has not been observed.
Multiple-chromosome sex systems in the darkling beetles Blaps gigas and Blaps gibba (Coleoptera, Tenebrionidae)
We have studied mitotic and meiotic chromosomes in the males of two species of Blaps: B. gigas and B. gibba. Karyological characteristics such as the occurrence of a multivalent configuration at diakinesis and two types of metaphase-II spreads support the notion that multiple-chromosome sex systems involving five chromosomes in B. gigas and eight chromosomes in B. gibba have developed in these species. Results obtained by means of silver staining and C-banding techniques suggest that the complex sex systems occurring in B. gigas and B. gibba may have originated from exchanges of terminal ribosomal genes among the Y chromosome and some autosomes.
ChemInform Abstract: Chemically Induced Chromosome Damage in Early-Developing Embryos of Anilocra Physodes L. (Crustacea, Isopoda) Following Exposure to Bis( dimethyltin(IV)chloro)protoporphyrin IX.
In order to obtain chromosome preparations from early-developing embryos of Anilocra physodes, a squash technique has been successfully employed. Results gathered after exposure of this material to bis[dimethyltin(IV)chloro]protoporphyrin IX {[(CH3)2SnCl]2 - Protoporphyrin IX} solutions at different exposure times suggest that this chemical complex is capable of producing abnormal metaphase and anaphase figures in proportion to its concentration and not to exposure length. Essentially, all of the chromosome abnormalities are classifiable as chromosome fragments mainly observed at the metaphase stage; chromosome bridges; and large decondensed chromosome regions.
Ag-NOR and C-banding analysis of spermatocyte chromosomes ofClavelina lepadiformis(Ascidiacea, Aplousobranchiata)
SUMMARYChromosome number n = 9 and 2n = 18 for Clavelina lepadiformis (Ascidiacea, Aplousobranchiata) from the Gulf of Palermo have been determined. Silver staining analysis of testicular cells reveals that within-individual variability in NOR banding patterns is present. Using the C-banding procedure, a very impressive heterochromatin amount seems to characterize the chromosome set of this species.
Karyotypes in two species of the genusHippocampus (Pisces: Syngnatiformes)
Diploid modal numbers of chromosomes 2n=48 forHippocampus ramulosus and 2n=44 forH. hippocampus, collected in the Gulf of Palermo in May 1985, are established. No sex-linked heteromorphic pairs are observed in the two species analyzed. The karyotype ofH. hippocampus seems to be a derived condition.
Multiple sex-chromosome system and other karyological characterizations of Pterotrachea hippocampus (Mollusca: Mesogastropoda)
Two modal diploid numbers of chromosomes were found for Pterotraches hippocampus Philippi (Mollusca: Mesogastropoda) collected from the Gulf of Palermo in 1990: 2n=31 and 32 for males and females, respectively. This, along with other karyological characteristics such as the occurrence of a trivalent configuration at diakinesis and two types of metaphase-II spreads in spermatocytes, supports the notion that a X1X2Y♂/X1X1X2X2♀ sex mechanism operates in the species investigated here. Silver nitrate procedure revealed an intraindividual variation in the Ag-staining pattern occurring in this species. The majority of the chromosome pair displayed terminal and/or interstitial heterochromatic block…
Karyotype analysis, nucleolus organizer regions and C-banding pattern of Eisenia foetida (oligochaeta, lumbricidae)
The diploid number 2n=22 and haploid number n=11 found for Eisenia foetida from Palermo, Italy, confirm earlier data for this species from other localities. Analyses of silver-stained and C-banded mitotic and meiotic chromosomes suggest that a single chromosome pair has active NORs which correspond with C-positive regions. The occurrence of nucleolus activity during spermatogenesis of E. foetida is ascertained.
Karyological and Molecular Characterization of Mullus surmuletus and Mullus barbatus(Pisces, Mullidae).
The modal diploid number of 44 chromosomes has been found in Mullus surmuletus and Mullus barbatus (Pisces, Mullidae). Two middle-sized subtelocentric chromosomes are involved in nucleolus organization (NORs) in both Mullus species. Despite similarity in the NOR location, valuable differences in the restriction pattern of the ribosomal genes have been observed.
Multiple chromosome polymorphism in the gobiid fish Gobius niger jozo L. 1758 (Pisces, Gobiidae).
By analysing chromosome preparation from 42 Gobius niger jozo specimens from the Gulf of Palermo (Sicily), four different karyotypes were observed: A (2n=52; NF=60), B (2n=51; NF=60), C (2n=50; NF=60) and D (2n=49; NF=60). A chromosome polymorphism due to Robertsonian fusion is present in this species.
Intra-populational and intra-individual mosaicisms of Uranoscopus scaber L. (Perciformes, Uranoscopidae)
Intra-populational and intra-individual mosaicisms of Uranoscopus scaber L. (Perciformes, Uranoscopidae)
Chemically induced chromosome damage in early-developing embryos ofAnilocra physodes L. (Crustacea, Isopoda) following exposure to bis[Dimethyltin(IV)Chloro]protoporphyrin IX
In order to obtain chromosome preparations from early-developing embryos of Anilocra physodes, a squash technique has been successfully employed. Results gathered after exposure of this material to bis[dimethyltin(IV)chloro]protoporphyrin IX {[(CH3)2SnCl]2 - Protoporphyrin IX} solutions at different exposure times suggest that this chemical complex is capable of producing abnormal metaphase and anaphase figures in proportion to its concentration and not to exposure length. Essentially, all of the chromosome abnormalities are classifiable as chromosome fragments mainly observed at the metaphase stage; chromosome bridges; and large decondensed chromosome regions.
.Chromosome sex determination and Y-autosome fusion in Blennius tentacularis Brunnich, 1765 (Pisces, Blennidae)
Diploid modal numbers of 2n=48 for females, and 2n=48 and 2n=47 for males of Blennius tentacularis caught in the Gulf of Palermo (Sicily) are established. Chromosome sex-determination is proposed for this species in which a Y-autosome fusion has been found.
Spermatocyte Chromosomes in Some Species of the Family Aplysiidae (Gastropoda, Opisthobranchia)
SUMMARYCounting spermatocyte bivalents, we have determined the haploid number n = 16 for Aplysia depilans and A. punctata, and n = 17 for A. limacina. We have confirmed n = 17 for Bursatella leachii. Male diakinetic bivalents are probably chiasmatic in all the species examined. The orders Nudibranchia and Notaspidea, possessing haploid values of 13 and 12 chromosomes respectively, seem to be more evolved than the other orders of the sub-class Opisthobranchia.
Karyotype analysis, nucleolar organizer regions(NORs), and C-banding pattern of Dicentrarchus iabrax(L.) and Dicentrarchus punctatus(Block, 1792)(Pisces, Perciformes) with evidence of chromosomal structural polymorphism.
Chromosomes of Dicentrarchus labrax and Dicentrarchus punctatus collected from the Gulf of Palermo are examined from kidney cells. The diploid chromosome number in both species is 2n=48. Ag-NOR and C-banding analyses revealed the presence of structural chromosomal polymorphism involving pair 1.A comparative analysis among the Giemsa, NOR- and C-banded karyotypes suggests that a close phylogenetic relationship between D. labrax and D. punctatus occurs. There are evidences for a conservative evolutionary trend in this genus.