Histological study of canine mammary gland during the oestrous cycle

The development of the mammary gland is a puzzling phenomenon and the research on this field has been focussed mostly on the carcinogenesis, with a less goal-oriented concern in basic histology. In order to determine the histological features of normal mammary gland in the different oestrous phases we used 39 non-pregnant female dogs of various breeds and ages. The animals were grouped in: pre-pubertal, pro-oestrous, oestrous, early and late dioestrous, early and late anoestrous phases. Major changes of the canine mammary histology throughout the oestrous cycle were identified in this study. A rudimentary gland with few ducts in the base of the nipple was observed in pre-pubertal female individuals and pubertal pro-oestrous female ones. In the oestrus, small inactive lobules associated with ductal branching and inconspicuous regressive changes were observed, while in early dioestrus, a ductal arborization was present. In late dioestrus, a complete lobuloalveolar differentiation and secretory capacity was achieved. The regressive histological features were abundant on early anoestrus, and markedly generalized on late anoestrus. The regressive process was longer in the more caudal gland pairs. This work provides baseline knowledge of canine mammary gland that may be relevant for interspecies comparative purposes and for pathologists dealing with mammary gland tumours.

Contrasting patterns of phenotypic variation linked to chromosomal inversions in native and colonizing populations of Drosophila subobscura

In fewer than two decades after invading the Americas, the fly Drosophila subobscura evolved latitudinal clines for chromosomal inversion frequencies and wing size that are parallel to the long-standing ones in native Palearctic populations. By sharp contrast, wing shape clines also evolved in the New World, but the relationship with latitude was opposite to that in the Old World. Previous work has suggested that wing trait differences among individuals are partially due to the association between chromosomal inversions and particular alleles which influence the trait under consideration. Furthermore, it is well documented that a few number of effective individuals founded the New World populations, which might have modified the biometrical effect of inversions on quantitative traits. Here we evaluate the relative contribution of chromosomal inversion clines in shaping the parallel clines in wing size and contrasting clines in wing shape in native and colonizing populations of the species. Our results reveal that inversion-size and inversion-shape associations in native and colonizing (South America) populations are generally different, probably due to the bottleneck effect. Contingent, unpredictable evolution was suggested as an explanation for the different details involved in the otherwise parallel wing size clines between Old and New World populations of D. subobscura. We challenge this assertion and conclude that contrasting wing shape clines came out as a correlated response of inversion clines that might have been predicted considering the genetic background of colonizers.

Species of Fusarium Isolated from River and Sea Water of Southeastern Spain and Pathogenicity on Four Plant Species

Species of Fusarium were isolated from water samples collected from the Andarax River and coastal sea water of the Mediterranean in Granada and Almería provinces of southeastern Spain. In total, 18 water samples were analyzed from the Andarax River, and 10 species of Fusarium were isolated: Fusarium anthophilum, F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum, F. solani, and F. sambucinum. In addition, five species were isolated from 33 sea water samples from the Mediterranean Sea: F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum, and F. solani. When considering the samples by their origins, 77.8% of the river water samples yielded at least one species of Fusarium, with F. oxysporum comprising 72.2% of the total isolates. In the case of marine water, 45.5% of the samples yielded at least one species of Fusarium, with F. solani comprising 36.3% of the total isolates. The pathogenicity of 41 isolates representing nine of the species collected from river and sea water during the study was evaluated on barley, kohlrabi, melon, and tomato. Inoculation with F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum F. solani, and F. sambucinum resulted in pre- and post-emergence damping off. Pathogenicity of Fusarium isolates did not seem to be related to the origin of the isolates (sea water or fresh water). However, the presence of pathogenic species of Fusarium in river water flowing to the sea could indicate long-distance dispersal in natural water environments.