CARYOLOGIA Vol. 54, no. 1, 2001

CARYOLOGIA Vol. 54, no. 1: 1-16, 2001

Characterization of the seed reserves in Tillandsia (Bromeliaceae) and ultrastructural aspects of their use at germination

AMBRETTA CECCHI FIORDI, MARIA ROSA PALANDRI, SILVIA TURICCHIA, GABRIELE TANI* and PIETRO Di FALCO

Dipartimento di Biologia Vegetale, Universita di Firenze, via La Pira, 4 - 50121 Firenze (Italy).

Abstract — The nature and the use of the reserves accumulated in the seed of

Tillandsia, a markedly epiphyte genus, are especially important in consideration of

the subsequent seedling development. As a matter of fact, the embryo radicle degenerates

precociously without emerging at the germination and the sole function of

the root system is that of anchoring to the substratum.

The present cytochemical and ultrastructural study carried out on mature seeds has

highlighted the presence of proteins and lipids, in both the endosperm and in the

cotyledon, which are both well-developed; in addition, the endosperm contains

starch and calcium oxalate. At germination the reserves, broken-down by enzymes,

are absorbed by the cotyledon in whose epidermis ultrastructural modifications,

correlated with this austorial function, appear. A part of the nutrients absorbed is

initially stored in the large vacuoles, of aleuronic origin, of the cotyledon

parenchyma. The result is a water uptake. It is in this manner that the water and

necessary nutrient needs of the seedling are satisfied during early development.

Key words: germination, seed, Tillandsia.


CARYOLOGIA Vol. 54, no. 1: 17-21, 2001

Nucleolar behaviour in a few legumes

R. MURUGESAN, N. CHANDRA, S.T. SANTHIYA, P.M. GOPINATH* and K.M. MARIMUTHU

Department of Genetics, Dr. A.L.M. Post Graduate Institute of Basic Medical Sciences, University of MadraTsa, ramani, Chennai -113,

INDIA.

Abstract — The nucleolus usually disintegrates at the end of prophase and gets reconstituted

at telophase. In a few instances it persists till meta- and ana-phases.

Persistence of nucleoli has been reported in a few angiosperms, algae and fungi. In

the light of the reports on the presence of persistent nucleoli in legumes it was of

interest to examine the root meristematic cells of twentyone leguminous plants belonging

to Papilionoideae for the persistence of nucleoli and ninteen of them exhibited

the phenomenon.


CARYOLOGIA Vol. 54, no. 1: 23-30, 2001

A molecular phylogenetic analysis in Gymnotus species (Pisces: Gymnotiformes) with inferences on chromosome evolution

FLORA M.C. FERNANDES-MATIOLI* and LURDES .F. ALMEIDA-TOLEDO

Laboratorio de Ictiogenetica, Departamento de Biologia, Institute de Biociencias, USP, Caixa Postal 11.461, CEP 05422-970, Universidade

de Sao Paulo, Sao Paulo, Brazil

Abstract — A phylogenetic analysis using 345 nucleotides sequenced from the mitochondrial

gene ND2 was carried out in the four Gymnotus species from the Upper-

Parana river system, Southeastern Brazil, G. carapo, G. pantherinus, G.

inaequilabiatus, and G. sylvius. A phylogeny is proposed in which G. pantherinus is

located as the most basal lineage within the group. G. carapo and G. sylvius lineages

present the most recent divergence; G, inaequilabiatus is the closest sister group in

relation to G. carapo and G. sylvius. New hypotheses of chromosome evolution in this

group of fish are proposed based on the phylogenetic tree reconstructed using the

sequence data. After an appraisal of karyotype data for species phylogeny

inferences, we suggest that karyotype data are useful for the early steps of

phylogenetic and chromosome evolution studies, and that the conjugation of

molecular and karyological approaches can improve the hypotheses formulation.


CARYOLOGIA Vol. 54, no. 1: 31-36, 2001

Localization of rDNA loci by Fluorescent In Situ Hybridization in some wild orchids from Italy (Orchidaceae)

S. D'EMERICO *'*, I. GALASSO 2, D. PIGNONE and A. SCRUGLI 3

1 Dipartimento di Biologia e Patologia Vegetale, Universita di Bari, Italy. 2 C.N.R., Istituto del Germoplasma, Bari, Italy.3 Dipartimento

di Scienze Botaniche, Universita di Cagliari, Italy.

Abstract — The 18S-5.8S-25S (pTa71) and 5S (pTa794) rDNA were used as

probes for in situ hybridization to reveal the physical localisation of ribosomal

genes in some species of orchids. Earlia robertiana (2n = 36) revealed one chromosome

pair with both pTa71 and pTa794 signals; Anacamptis papilionacea (2n = 32)

showed two pairs of 5S rDNA and one pair of 18S-25S sites; A. morio (2n = 36)

had two pairs of 18S-25S rDNA and one pair of 5S sites; the natural hybrid A. x

gennarii (A. morio x A. papilionacea, 34 chromosomes) showed three 18S-25S and

three 5S rDNA sites; finally, A. collina (2n = 36) showed only one pair of 18S-25S

rDNA and one pair of 5S rDNA sites. This preliminary contribution indicates that

repetitive DNA sequences in orchids may prove very useful for the understanding of

evolutionary trends.


CARYOLOGIA Vol. 54, no. 1: 37-57, 2001

Cytotaxonomical notes on some rare endemic species of Allium (Alliaceae) from Greece

S. BRULLO*, A. GUGLIELMO, P. PAVONE and C. SALMERI

Dipartimento di Botanica, Universita di Catania, Via A. Longo, 19.1-95125 Catania, Italia

Abstract — Five Greek endemic species of Allium (A. meteoricum, A. parnassicum,

A. pilosum, A. luteolum and A. frigidum) are examined. The study, based on

field and herbarium investigations, allowed to better define the morphology, karyology

and chorology of these critical taxa as well as their relationships.


CARYOLOGIA Vol. 54, no. 1: 59-71, 2001

Genotoxic effects of chromium on polytene chromosomes of Chironomus riparius Meigen 1804 (Diptera, Chironomidae)

P. MlCHAILOVA, N. PETROVA2, G. SELLA3, S. BOVERO3, L. RAMELLA3, F. REGOLI and V. ZELANO5

'Bulgarian Academy of Sciences, Institute of Zoology, boul. Tzar Osvoboditel 1, 1000 Sofia, Bulgaria. 2Russian Academy of Sciences,

Institute of Zoology, Universitetskaya nab.l, 199034 St.Petersburg, Russia. 3 Universita degli Studi di Torino, Dipartimento di Biologia

Animale, via Accademia Albertina 17, 10123 Turin, Italy. 4Universita di Ancona, Istituto di Biologia e Genetica, via Raineri Monte

d'Ago, 60100 Ancona, Italy. 'Universita degli Studi di Torino, Dipartimento di Chimica Analitica, via P. Giuria 5, 10125 Turin, Italy.

Abstract — Genotoxic effect as tested of chronic exposure to three different concentrations

of Chromium (III) on polytene chromosomes of larvae of Chironomus

riparius (syn. Chironomus thummi) from the embryonic stage to the IV larval instar for

two successive generations. In chromosomes AB, CD, EF and G significant differences

of chromosome aberrations were found between exposed and control larvae

as well as changes in functional activity (induction of novel puffs not corresponding

to those induced during normal larval development in arms A, B, C and E,

telomeric and centromeric decondensations especially at telomeres of chromosome

G and arm C.). No significant differences were found between the effects of the three

treatments nor between the two generations. In chromosome G the Balbiani Ring

system (where some permanently active regions are involved in transcription of

salivary proteins) appeared as a model for studying the response of the genome to Cr

(III) treatment. In approximately one-third of the cells of the exposed larvae, the

activity of the Balbiani rings BRc and BRb was reversed. In 10% of the cells of both

generations of treated larvae, deletion or collapse of BRc was observed. Pomponlike

G chromosomes were present in 6% of the cells. This type of chromoosme

appeared either in a very decondesed or in a highly condensed state. In 5 % of the

treated larvae the apical region of the chromosome G folded back so that the

nucleolar organizer region appeared as if it was at the end of the chromosome.

These structural and functional chromosomal changes are interpreted as a reaction

of the genome to stressful rearing conditions.


CARYOLOGIA Vol. 54, no. 1: 73-81, 2001

Long-term starvation effects on Mus musculus hepatocyte nuclear phenotypes

R. P. MATEUS* and S. R. TABOGA

Department of Biology, IBILCE, UNESP, Sao Jose do Rio Preto - SP, Brazil.

Abstract — Starvation is a physiologic stress and can significantly alter the structure of

hepatic cells. This work aims to detect morphological changes in mice hepatocyte under

starvation physiologic stress, based on silver staining technique. Fourteen 21 day old male

mice (Mus musculus) were used, 5 as control, 5 submitted to 72 hours of starvation, and 4

were refed during 72 hours after 72 hours of starvation. After liver imprint, 15 nuclei per

mouse and their respective nucleoli were outlined in millimetric paper and their areas

were obtained. The results, in mm2, were transformed into mm2. The number of nucleoli

per nuclei were also counted. After starvation, a statistically significant rise in nuclear and

nucleolar areas occurred and no significant increase in the number of nucleoli was

observed. The refeeding caused a partial recovery of the nuclear area, no significant

change in the nucleolar area and a statistically significant increase in the number of nucleoli.

Therefore, starvation can be considered as a modifier agent of the chromatinic

structure, leading to an increase of the nuclear and nucleolar areas probably due to an

increment of RNA and protein synthesis. The recovery of the stress (re-feeding) did not

presented a decrease of nucleolar area and evidenced a nucleoli fragmentation, probably

to increase more the protein synthesis and/or due to its cycle during the interphase.


CARYOLOGIA Vol. 54, no. 1: 83-96, 2001

Cytogenetics of Adamanotus uncotibialis Jacobs (Heteroptera: Aradidae)

D. H. JACOBS and H. LIEBENBERG

1 Department of Zoology and Entomology, University of Pretoria, Pretoria 00022 ,D epartment of Genetics.University of Pretoria,

Pretoria, 0002, South Africa.

Abstract —The cytogenetics of Adamanotus uncotibialis (Aradidae, Carventinae)

with a chromosome number of 2n=16XY is described and figured. An idiogram of

the karyotype, based on chromosome area measurements by means of an image

analyzer, is presented and the method, its advantages and limitations is described

and discussed. A chiasma analysis of seven individuals is given and briefly discussed.

The occurrence of abnormal meiocytes (including malorientated chromosomes

and bivalents at metaphase I and II, laggards and late segregating chromosomes

at anaphase I and II, chromatid bridges at anaphase II and tetraploid and

unbalanced metaphase II cells) at a low frequency is reported and it is suggested

that they originate because of dicentric spindle attachment of the chromosomes.


CARYOLOGIA Vol. 54, no. 1: 97-101, 2001

Molecular analysis of Salamander family: the new alpine salamander Salamandra atra aurorae

AURORA PEDERZOLI*, PAOLA AZZONI and MAURO MANDRIOLI

Dipartimento di Biologia Animale, Universita degli Studi di Modena e Reggio Emilia, via Campi 213/d, 41100 Modena, Italy.

Abstract — A portion of the mitochondrial DNA from the 3' terminal of gene 12S

rRNA to the 5' extremity of 16S rRNA gene has been amplified by PCR from Salamandra

atra aurorae genomic DNA in order to define the taxonomic position of S.

atra aurorae within the Salamandra species. Analysis of the molecular data indicated

that S. a. aurorae is quite different from S. salamandra, whereas S. a. aurorae

and S. a. atra are more similar, although their mitochondrial DNA present several

mutations. Our analysis suggested therefore that S. a. aurorae could really represent

a new subspecies of alpine salamander. Finally, on the basis of the rate of sequence

divergence, we could suggest that S. a. atra and S. a. aurorae diverged about three

million years ago.