Articular cartilage is a highly specialized tissue that covers the surface of synovial joints, allowing its smooth articulation. Cartilage is synthesized and maintained by chondrocytes, and is composed primarily of water, proteoglycan (principally aggrecan), and collagen (1). Type II collagen fibrils are arranged to form a fibrillar network within which are trapped aggrecan molecules that pull water into the tissue. These two components provide cartilage with its tensile strength and the ability to resist compression. The degradation of cartilage is one of the key features of the arthritides and results in disability.The degradation of cartilage in vitro and in vivo is believed to be mediated by neutral endopeptidases of the metalloproteinase class of enzymes (2). Two families in this class that have been implicated are the matrix metalloproteinase (MMP) and ADAM families (2,3).

Polymorphism at six microsatellite loci was used to study genetic variability and population structure in six geographically distant natural populations of European hake (Merluccius merluccius L.). Four hundred and eighty-three individuals were sampled from Trondheimsfjord in Norway, the Celtic Sea, the southern Bay of Biscay, Faro off Portugal, the Mediterranean Sea north of the coast of Tunisia and the Adriatic Sea. Population subdivision was found between Mediterranean and Atlantic samples, theta = 0.029 (P < 0. 001). No substructuring was found between samples within the Mediterranean Sea, theta = 0.003 and RST = 0.007 (P > 0.05). The Atlantic population structure appears to be more complex than previously suggested by the placement of stock boundaries by the International Council for the Exploration of the Seas (ICES). Analyses based on various models of microsatellite evolution all suggest that differentiation exists between Bay of Biscay and Portugese samples, theta = 0.013 (P < 0.001), RST = 0.036 (P < 0. 001) which are currently managed as one stock. By contrast, fixation indices indicated no differentiation between southern Bay of Biscay samples and Celtic Sea samples, theta = 0.003 (P = 0.02), phiST = 0. 007 (P = 0.10) which are managed as separate stocks. These results suggest that if the observed trends are stable through time, current management policy of European hake may need revision.

We have used real-time quantitative reverse transcriptase PCR (TaqMan2) to quantify the expression of the four tissue inhibitor of metalloproteinases (Timp) genes in mouse tissues during development and in the adult. Among the four Timp genes, Timp-4 shows the most restricted pattern of expression, with highest RNA levels in brain, heart and testes. These data indicate that in the brain, Timp-4 transcripts are temporally regulated during development, becoming more abundant than those of the other Timps after birth. Cloning of the Timp-4 gene confirmed a five-exon organization resembling that of Timp-2 and Timp-3, and like all Timps, Timp-4 is located within an intron of a synapsin gene. Ribonuclease protection analysis and 5h-rapid amplification of cDNA ends PCR identified multiple transcription starts for Timp-4 from brain and heart mRNA. The promoter region of Timp-4 was functional in transient transfection analysis

Polymorphism at five microsatellite loci were screened to determine the genetic variability and the temporal stability of population structure in natural populations of European hake (Merluccius merluccius, L.) within the Bay of Biscay. In addition, the control region (900 bp) and two protein coding genes (ATPase, subunits 6 and 8, 842 bp and a partial sequence of the ND1, 800 bp) of the mitochondrial DNA (mtDNA) were sequenced from geographically distant populations from the extremes of the species range. One hundred individuals from either side of a supposed stock boundary within the bay were collected in autumn 1997. This sampling strategy was repeated during hake spawning seasons in late spring of 1998 and 1999. Low levels of population subdivision were found between putative populations within years. Similarly, low levels of differentiation were found between autumn 1997 northern samples and spring 1998 southern samples which were collected 7 months later on spawning grounds. These results are discussed in relation to ecological, behavioural and oceanographic information. Sampling effects, which may influence these results, are also discussed. Theta (theta) estimates were significantly different from zero in every other pairwise comparison between geographical areas (north and south of the Bay of Biscay) and between years within the same area (P<0.05). Hierarchical analysis of molecular variance (AMOVA) does not confirm the temporal persistence of population structure. These results are discussed in relation to variance in reproductive success, and temporal spawning patterns, which may exist within the bay. mtDNA variability was very low between geographically distant samples from Norway and the Mediterranean Sea with only 10 variable sites found in a total of 2542 bp of mtDNA, these differences being exclusively in the D-loop.

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