<Emphasis Type="Italic">In vitro</Emphasis> organogenesis of <Emphasis Type="Italic">Passiflora alata</Emphasis>

Passiflora alata in vitro organogenesis was studied based on explant type, culture medium composition, and incubation conditions. The results indicated that the morphogenic process occurred more efficiently when hypocotyl segment-derived explants were cultured in media supplemented with cytokinin and AgNO₃ incubated under a 16-h photoperiod. The shoot bud elongation and plant development were obtained by transferring the material to MSM culture medium supplemented with GA₃ and incubated in flasks with vented lids. Histological analyses of the process revealed that the difficulties in obtaining plants could be related to the development of protuberances and leaf primordia structures, which did not contain shoot apical meristem. Roots developed easily by transferring elongated shoots to 1/2 MSM culture medium. Plant acclimatization occurred successfully, and somaclonal variation was not visually detected. The efficiency of this organogenesis protocol will be evaluated for genetic transformation of this species to obtain transgenic plants expressing genes that can influence the resistance to Cowpea aphid borne mosaic virus.     

Is zinc deficiency a cause of subclinical hypothyroidism in Down syndrome?

In Down syndrome there is a high incidence of overt or subclinical hypothyroidism as well as some immunological defects, early thymic involution associated to low serum zinc levels. Zinc supplementation to the diet has been reported to transiently improve thymic function; moreover thymic function has been shown to be in relation with the pituitary-thyroid axis. The aim of this study was to evaluate if, in Down patients, zinc therapy could improve also thyroid function, by determining serum levels of total and free thyroid hormones and basal TSH levels. In 52 patients studied, we found a high incidence of subclinical hypothyroidism (30%); in 17 patients treated with zinc sulphate we showed a reduction of FT3. More significantly, we detected 9 patients with low zinc levels in which zinc supplementation improved thyroid function, thus reducing the incidence of subclinical hypothyroidism.     

Morphometric and functional study of apoptotic cell chromatin

Apoptosis is usually characterized by profound morphological nuclear changes. Chromatin undergoes a progressive condensation that eventually involves all the nucleus. At earlier stages chromatin appears as divided in compact and diffuse areas, while the nuclear pores disappear from the nuclear envelope that surrounds the compact areas, and cluster around diffuse chromatin. Here we have performed a morphometric study on the different chromatin areas of freeze-fractured apoptotic cell nuclei in order to investigate its morphometric and functional organization. We have found large portions of inactive chromatin aggregations corresponding to the dense cap-shaped patches, while domains of nucleosomic fibres have been identified in the diffuse chromatin areas. The correlation of the nucleosomic fibre/diffuse chromatin domain with the nuclear pore clusters is demonstrated, and its implications with a possible residual nuclear activity are discussed.     

X/Y translocation in a family with Leri-Weill dyschondrosteosis

An X/Y translocation associated with Leri-Weill dyschondrosteosis (LWD) was detected in a boy and in his mother. FISH analysis with specific probes for SHOX and SRY displayed no signal on the der(X), while one signal for SHOX was detected on the normal X chromosome in the mother, and one signal each for SHOX and SRY was detected on the normal Y chromosome in the proband.     

Characterization of a new TSPY gene family member in Yq (TSPYq1)

We investigated subinterval 6E on the human Y chromosome, a region frequently deleted in infertile males. YAC yOX17, mapped within subinterval 6E by STS-PCR, was analyzed for the presence of new genes. TSPYq1, a member of the TSPY multi-copy gene family, was isolated and characterized from a yOX17 cosmid subclone. PCR and FISH analysis performed on normal subjects and on patients with microdeletions of Yq suggested the presence of multiple copies of TSPY in Yq.     

Identification in chromosome 8q11 of a region of homology with the g1 amplicon of the Y chromosome and functional analysis of the BEYLA gene

The male-specific region (MSY) of the Y chromosome contains genes involved mainly in male sex determination and in spermatogenesis. The majority of genes involved in male fertility are localized in multiple copies in the long arm of the Y chromosome, within specific regions defined as "ampliconic regions." It has been suggested that these genes derived from X-linked or autosomal ancestors during evolution, providing a benefit for male fertility when transposed onto the Y chromosome. So far, the autosomal origin has been demonstrated only for two MSY genes, DAZ and CDY. In the present study we report on the identification within chromosome 8q11.2 of a region homologous to the g amplicon, containing the VCY2 (approved gene symbol BPY2), TTTY4, and TTTY17 genes. A search for ancestor genes within the 8q11.2 region allowed us to identify a gene named BEYLA and to characterize the genomic organization and the expression patterns of this gene.