Development of secondary palate requires strict regulation of ECM remodeling: sequential distribution of RECK, MMP-2, MMP-3, and MMP-9

We have evaluated RECK (reversion-inducing-cysteine-rich protein with Kazal motifs), MMP-2 (matrix metalloproteinase-2), MMP-3, and MMP-9 involvement during palate development in mice by using various techniques. Immunohistochemical features revealed the distribution of RECK, MMP-2, and MMP-3 in the mesenchymal tissue and in the midline epithelial seam at embryonic day 13 (E13), MMPs-2, -3, and -9 being particularly expressed at E14 and E14.5. In contrast, RECK was weakly immunostained at these times. Involvement of MMPs was validated by measuring not only their protein expression, but also their activity (zymograms). In situ hybridization signal (ISH) for RECK transcript was distributed in mesenchymal and epithelial regions within palatal shelves at all periods evaluated. Importantly, the results from ISH analysis were in accord with those obtained by real-time polymerase chain reaction. The expression of RECK was found to be temporally regulated, which suggested possible roles in palatal ontogeny. Taken together, our results clearly show that remodeling of the extracellular matrix is finely modulated during secondary palate development and occurs in a sequential manner.

Revision and cladistic analysis of Isoctenus and description of a new neotropical genus (Araneae, Ctenidae, Cteninae)

A cladistic analysis was applied to test the monophyly of the genus Isoctenus. The data matrix comprised 28 taxa scored for 53 morphological and two behavioural characters. The analysis resulted in two equally parsimonious trees of 89 steps. The strict consensus was used to discuss the relationships of Isoctenus and related Cteninae genera. Ctenopsis Schmidt is synonymized with Isoctenus. Isoctenus foliifer Bertkau, I. strandi Mello-Leitao, I. eupalaestrus Mello-Leitao, I. janeirus (Walckenaer), I. coxalis (Pickard-Cambridge), I. corymbus Polotow, Brescovit & Pellegatti-Franco and I. malabaris Polotow, Brescovit & Ott are maintained in Isoctenus. Four species currently included in Ctenus are transferred to Isoctenus: I. griseolus (Mello-Leitao) comb. nov., I. taperae (Mello-Leitao) comb. nov., I. herteli (Mello-Leitao) comb. nov. and I. minusculus (Keyserling) comb. nov. The following specific names are synonymized: Ctenus sanguineus Walckenaer, C. semiornatus Mello-Leitao and Ctenopsis stellata Schmidt with Isoctenus janeirus (Walckenaer), Ctenus mourei Mello-Leitao with Isoctenus herteli (Mello-Leitao) and Ctenus pauper Mello-Leitao with Isoctenus strandi Mello-Leitao. Isoctenus sigma Schenkel, described from French Guiana, is transferred to Ctenus. Four species are newly described: Isoctenus areia sp. nov. from Paraiba, Brazil, I. charada sp. nov. and I. segredo sp. nov. from Parana, Brazil, and I. ordinario sp. nov. from south and south-eastern Brazil and north-eastern Argentina. Isoctenus latevittatus Caporiacco is considered species inquirenda. Parabatinga gen. nov. is proposed to include Ctenus brevipes Keyserling. The following synonymies are established: Ctenus taeniatus Keyserling, C. tatarandensis Tullgren, C. anisitsi Strand, C. atrivulvus Strand, C. mentor Strand, C. brevipes brevilabris Strand, Isoctenus masculus Mello-Leitao and Ctenus birabeni Mello-Leitao with Parabatinga brevipes (Keyserling) comb. nov. (C) 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155, 583-614.

Tridiagonal canonical matrices of bilinear or sesquilinear forms and of pairs of symmetric, skew-symmetric, or Hermitian forms

Tridiagonal canonical forms of square matrices under congruence or *congruence, pairs of symmetric or skew-symmetric matrices under congruence, and pairs of Hermitian matrices under *congruence are given over an algebraically closed field of characteristic different from 2. (C) 2008 Elsevier Inc. All rights reserved.