Catalase gene is associated with facial eczema disease resistance in sheep

Facial eczema (FE) is a hepatogenous photosensitization disease of ruminant animals, particularly in sheep which vary widely in their susceptibility to the disease. The liver damage is caused by the mycotoxin, sporidesmin. There is evidence that the toxicity of sporidesmin is due to its ability to generate 'active oxygen' species. We evaluated the catalase gene, which encodes an enzyme with antioxidant functions, as a candidate for determining the susceptibility of sheep to the disease. Two microsatellite markers, OarSHP3 and OarSHP4, which flank the sheep catalase gene, were isolated from a Yeast Artificial Chromosome (YAC) clone. These markers mapped the catalase locus by linkage to ovine chromosome 15. Eleven informative markers spaced throughout chromosome 15, inclusive of the catalase marker OarSHP4, gave no significant linkage with the disease traits when analysed in four outcross resource pedigrees. However, OarSHP3 and OarSHP4 allele frequencies showed significant differences between FE resistant and susceptible selection-lines. Comparison of sequences of catalase cDNAs from sheep of resistant and susceptible lines showed only two silent mutations. A single nucleotide polymorphisms (KP1) in exon 6 of the catalase gene also showed significant differences in allele frequencies between the selection lines. The lack of evidence for linkage in outcross pedigrees, but the significant association in the genetic lines, implies that catalase is involved in determining the susceptibility of sheep to facial eczema, and that the candidate gene's effect is probably recessive or minor.

Silica sol as a nanoglue: flexible synthesis of composite aerogels

Low-density nanoscale mesoporous composites may be readily synthesized by adding a colloidal or dispersed solid to an about-to-gel silica sol. The silica sol can "glue" a range of chemically and physically diverse particles into the three-dimensional silica network formed upon gelation. If the composite gel is supercritically dried so as to maintain the high porosity of the wet gel, a composite aerogel is formed in which the nanoscopic surface and bulk properties of each component are retained in the solid composite. The volume fraction of the second solid can be varied above or below a percolation threshold to tune the transport properties of the composite aerogel and thereby design nanoscale materials for chemical, electronic, and optical applications.

Identification and characterization of a recombinant metallothionein protein from a marine alga, Fucus vesiculosus

A cDNA library was constructed from macroalgae adapted to prolonged elevated environmental copper levels. To investigate the possible existence of a metallothionein (MT) gene, the library was screened with degenerate probes designed using plant MT cysteine-rich motifs. A gene was identified (1229 bp) with a putative open reading frame (204 bp) encoding a 67-amino-acid protein exhibiting several characteristic features of MT proteins, including 16 cysteine residues (24%) and only one aromatic residue. Although the protein sequence showed high identity with plant and invertebrate MTs, it contained a unique 'linker' region (14 amino acid residues) between the two putative metal-binding domains which contained no cysteine residues. This extended linker is larger than the tripeptide found in archetypal vertebrate MTs, but does not conform either with the 40-amino-acid linkers commonly found in plant MT sequences. An S-peptide Fucus MT fusion protein expressed in Escherichia coli exhibited a relative molecular mass of approximately 14 kDa. The recombinant fusion bound seven Cd ions, of which 50% were dissociated at pH 4.1. Under anaerobic conditions, the Cd ions were displaced by Cu(I), which associated with the protein at a ratio of 13:1. Laboratory exposure of F. vesiculosus to elevated copper resulted in induction of the MT gene. Thus this paper describes, for the first time, an MT gene identified from macroalgae which is induced by copper exposure and whose encoded protein product binds cadmium and copper.

Familial antiphospholipid antibody syndrome: criteria for disease and evidence for autosomal dominant inheritance

OBJECTIVE

To develop diagnostic criteria for a familial form of antiphospholipid antibody syndrome (APS), identify families with >1 affected member, examine possible modes of inheritance, and determine linkage to potential candidate genes.

METHODS

Family members of probands with primary APS were analyzed for clinical and laboratory abnormalities associated with APS. Families with > or =2 affected members were analyzed by segregation analysis and typed for candidate genetic markers.

RESULTS

Seven families were identified. Thirty of 101 family members met diagnostic criteria for APS. Segregation studies rejected both environmental and autosomal recessive models, and the data were best fit by either a dominant or codominant model. Linkage analysis showed independent segregation of APS and several candidate genes.

CONCLUSION

Clinical and laboratory criteria are essential to identify the spectrum of disease associated with APS. We believe a set of criteria was developed that can precisely define affected family members with APS. Modeling studies utilizing these criteria strongly support a genetic basis for disease in families with APS and suggest that a susceptibility gene is inherited in an autosomal dominant pattern. However, in these families, APS was not linked with HLA, Fas, or other candidate genes, including beta2-glycoprotein 1, HLA, T cell receptor beta chain, Ig heavy chain, antithrombin III, Fas ligand, factor V, complement factor H, IgK, and Fas.

A novel human gene, WSTF, is deleted in Williams syndrome

Williams syndrome (WS) is a developmental disorder caused by deletion of multiple genes at chromosome 7q11.23. Here, we report the identification and characterization of a novel gene, WSTF, that maps to the common WS deletion region. WSTF encodes a novel protein of 1425 amino acids with unknown function. It contains one PHD-type zinc finger motif followed by a bromodomain. Both motifs are found in many transcription regulators, suggesting that WSTF may function as a transcription factor. WSTF is ubiquitously expressed in both adult and fetal tissues. The WSTF gene consists of 20 exons spanning about 80 kb. Fluorescence in situ hybridization analysis shows that WSTF is deleted in 50/50 WS individuals. Hemizygous deletion of WSTF may contribute to WS.

Complete physical map of the common deletion region in Williams syndrome and identification and characterization of three novel genes

Williams syndrome (WS) is a contiguous gene deletion disorder caused by haploinsufficiency of genes at 7q11.23. We have shown that hemizygosity of elastin is responsible for one feature of WS, supravalvular aortic stenosis (SVAS). We have also implicated LIM-kinase 1 hemizygosity as a contributing factor to impaired visual-spatial constructive cognition in WS. However, the common WS deletion region has not been completely characterized, and genes for additional features of WS, including mental retardation, infantile hypercalcemia, and unique personality profile, are yet to be discovered. Here, we present a physical map encompassing 1.5 Mb DNA that is commonly deleted in individuals with WS. Fluorescence in situ hybridization analysis of 200 WS individuals shows that WS individuals have the consistent deletion interval. In addition, we identify three novel genes from the common deletion region: WS-betaTRP, WS-bHLH, and BCL7B. WS-betaTRP has four putative beta-transducin (WD40) repeats, and WS-bHLH is a novel basic helix-loop-helix leucine zipper (bHLHZip) gene. BCL7B belongs to a novel family of highly conserved genes. We describe the expression profile and genomic structure for each of these genes. Hemizygous deletion of one or more of these genes may contribute to developmental defects in WS.

A novel human gene FKBP6 is deleted in Williams syndrome

Williams syndrome (WS) is a developmental disorder caused by haploinsufficiency of genes at 7q11.23. We have shown that hemizygosity of elastin is responsible for one feature of WS, supravalvular aortic stenosis. We have also implicated LIM-kinase 1 hemizygosity as a contributing factor to impaired visual-spatial constructive cognition in WS. Here we identify and characterize a novel gene, FKBP6, within the common WS deletion region. FKBP6 shows homology to the FK-506 binding protein (FKBP) class of immunophilins. FKBP6 has a putative N-terminal FK-506 binding and peptidylproyl isomerase (rotamase) domain and, like known high-molecular-weight FKBPs, an imperfect C-terminal tetratricopeptide repeat domain. FKBP6 is expressed in testis, heart, skeletal muscle, liver, and kidney. FKBP6 consists of nine exons and is completely contained within a 35-kb cosmid clone. Fluorescence in situ hybridization experiments show that FKBP6 gene is deleted in 40/40 WS individuals. Hemizygous deletion of FKBP6 may contribute to certain defects such as hypercalcemia and growth delay in WS.

Development of mini-gel technology in two-dimensional electrophoresis for mass-screening of samples: application to tears

Despite the extensive literature available on tear proteins and lipids, very little has been reported on the tear fluid as a whole and it's changes in contact lens wear or ocular diseased patients. Initially a human reflex tear two-dimensional map was created by Molloy et al. (Electrophoresis 1997, 18, 2811-2815), using this information a process for mass-screening was established. The large format two-dimensional technique was evaluated, using a basal tear reference map, and modified to describe a fast, efficient and cost effective method of protein separation. The use of one pH 3-10 18 cm nonlinear immobilised pH gradient (IPG) strip and two mini-gels for the second-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) results in an effective separation of tear proteins which will be applied in diagnostic studies of tear samples.

Genetic aspects of supravalvular aortic stenosis

Supravalvular aortic stenosis (SVAS) occurs as an autosomal dominant trait or as part of the phenotype of the usually sporadic condition Williams syndrome. SVAS is the result of mutation or deletion of the elastin gene (ELN), located at chromosome 7q11.23. Thus, SVAS may be more appropriately termed an elastin arteriopathy. Studies have demonstrated various point mutations and intragenic deletions of ELN resulting in nonsyndromic SVAS. Individuals with Williams syndrome are hemizygous for the elastin gene, owing to a 1 to 2 megabase deletion of a portion of the long arm of chromosome 7 that encompasses ELN. This submicroscopic deletion is readily detected by fluorescent in-situ hybridization, useful in the diagnosis of Williams syndrome. The severity of SVAS is quite variable, both in series of Williams syndrome patients and within SVAS kindreds, suggesting that other genetic factors are involved in expression of the phenotype. Experiments with elastin knockout mice will likely yield clues regarding the role of elastin in arterial morphogenesis and the pathogenesis of obstructive vascular disease.

Current methods for stallion semen cryopreservation: a survey

Various factors affect the success of AI with frozen-thawed semen in horses. Stallion variability is thought to be one of the major factors, but semen processing and evaluation techniques, thawing protocols, packaging systems and timing of insemination are far from standardized among laboratories. Our objective was to survey current methods for stallion semen cryopreservation used commercially around the world. From the answers to the questions in the survey, we attempted to provide an overview of procedures that are standard as well as those that are used by only few laboratories and to review critically the efficacy of these procedures. Twenty-five questionnaires were sent to individuals or laboratories in 14 countries that were i.v. involved in freezing stallion semen for commercial purposes. Questionnaires were returned from 10/14 countries with 21/25 (84%) of the addresses responding. From the responses, it became evident that most of prefreezing, freezing and thawing and post-thawing processing procedures were far from standardized. The great variety of procedures makes it difficult to accept any of them as reliable. In order to increase the credibility of AI technology in the horse, laboratories need to standardize processing methods as well as the record-keeping systems. In addition, it is evident that no group of research mares is large enough to provide meaningful fertility data. It is therefore imperative to have multicentered collaborative studies to record and disseminate information about methods and the corresponding fertility rate. to gain valuable information and be able to compare different protocols.

Tear changes in contact lens wearers following overnight eye closure

PURPOSE

Tear protein composition alters during eye closure, by becoming rich in secretory IgA (sIgA) and certain complement proteins. This may reflect altered ocular defense mechanisms during eye closure. Since overnight wear of contact lenses (CLs) is associated with an increased risk of corneal infection and inflammation, this study aimed to quantify tear protein changes with overnight soft CL wear.

METHODS

Non-stimulated tears were collected from 9 CL wearers prior to CL wear (baseline), after daily CL wear, and after 8 h sleep. Lenses were removed following wear and were extracted in 80% urea at 95 degrees C. Secretory IgA, complement C3 and C4, were measured using ELISA and total protein using the Pierce BCA assay. Assays were performed on tear samples and CL extracts.

RESULTS

Baseline tear protein concentrations were: 0 total tear protein (9.37 +/- 2.97 mg/mL), C3 (4.4 +/- 2.1 micrograms/mL), C4 (0.1 +/- 0.1 micrograms/mL), and sIgA (0.84 +/- 0.34 mg/mL). There were no differences in any protein levels between daily CL wear and no CL wear (p > 0.05). Following sleep, protein concentrations were: total tear protein (43.64 +/- 24.30 mg/mL), C3 (72.5 +/- 49.9 micrograms/mL), C4 (6.7 +/- 5.2 micrograms/mL), and sIgA (5.53 +/- 5.15 mg/mL). Total protein extracted from CLs after daily wear was 90 +/- 27 micrograms/CL and, after overnight wear, 152 +/- 24 micrograms/CL. Negligible levels of C3, C4 and sIgA were recovered from CL extracts.

CONCLUSIONS

Uncomplicated daily use of soft CLs does not appear to alter certain tear proteins compared with baseline levels. Uptake of these proteins by the CL does not appear to deplete the tear protein levels. Overnight levels of all tear proteins were increased, compared to daily CL wear.

Establishment of the human reflex tear two-dimensional polyacrylamide gel electrophoresis reference map: new proteins of potential diagnostic value

To understand the changes in protein expression associated with various physiological states as well as the development of pathological eye disease, we have begun to map the protein components of normal human reflex tears. An analytical reference map of normal human reflex tears was created using two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) with pH 3.5-10 immobilized pH gradients (IPGs). Micropreparatively loaded gels were transferred to polyvinylidene difluoride (PVDF) and analysed by a combination of N-terminal sequence tagging and amino acid compositional analysis. Thirty spots were sequence tagged, resulting in identification of six different proteins (lipocalin, lysozyme, lactotransferrin, zinc-alpha-2 glycoprotein, cystatin S, cystatin SN) that matched to entries in the SWISS-PROT database. A group of N-terminally blocked proteins was clearly identified from SWISS-PROT by amino acid analysis, isoelectric point (pI) and molecular weight (Mr). A number of highly expressed protein components remain unidentified despite being subjected to amino acid analysis and Edman sequencing. A majority of the abundant proteins showed varying degrees of charge heterogeneity attributed to post-translational processing such as glycosylation and N-terminal truncation. We have identified a previously undescribed protein that we have named lacryglobin. This protein displays strong homology with mammaglobin, a protein overexpressed in breast cancer. The discovery of this homologue in tears offers the potential for disease diagnosis by screening tear fluid proteins.

Elastin point mutations cause an obstructive vascular disease, supravalvular aortic stenosis

Supravalvular aortic stenosis (SVAS) is an inherited obstructive vascular disease that affects the aorta, carotid, coronary and pulmonary arteries. Previous molecular genetic data have led to the hypothesis that SVAS results from mutations in the elastin gene, ELN. In these studies, the disease phenotype was linked to gross DNA rearrangements (35 and 85 kb deletions and a translocation) in three SVAS families. However, gross rearrangements of ELN have not been identified in most cases of autosomal dominant SVAS. To define the spectrum of ELN mutations responsible for this disorder, we refined the genomic structure of human ELN and used this information in mutational analyses. ELN point mutations co-segregate with the disease in four familial cases and are associated with SVAS in three sporadic cases. Two of the mutations are nonsense, one is a single base pair deletion and four are splice site mutations. In one sporadic case, the mutation arose de novo. These data demonstrate that point mutations of ELN cause autosomal dominant SVAS.

Effect of hydrogel lens wear on the major tear proteins during extended wear

PURPOSE

The purpose of the present study was to determine the whether contact lens wear disturbed the levels of tear proteins and to further determine whether this was a transient or continuous disruption.

METHODS

Lactoferrin, lysozyme and albumin were quantitated from tears of neophyte patients and were compared with the levels of these proteins in contact lens wearers after one and six nights and 6 months of extended wear. The quantitation of these tear proteins was performed by sandwich ELISA and turbidimetric assay.

RESULTS

Results showed that there were no statistically significant changes in the concentration of any of the proteins investigated.

CONCLUSIONS

Extended wear of hydrogel lenses does not appear to alter the concentration of the major tear film proteins, indicating that the tear film is constantly replenished to maintain protein levels, which are depleted due to protein adsorption to the lens surface.

Complement and complement regulatory proteins in human tears

PURPOSE

The complement system is part of the innate defense system of the body, and it contributes to inflammatory conditions. The current study examined tears for the presence of complement components, the activity of the components, and the presence of regulatory components.

METHODS

The significance of a functional complement system in tears was examined in four ways. First, the presence and concentration of complement components in tear samples (open-eye, closed-eye, and reflex tears) was examined by sandwich enzyme-linked immunosorbent assay. Second, the presence of an active pathway in each tear type was established by supplementation of complement-deficient sera. Third, Western blotting of tear samples was used to determine whether complement components were activated in tears. Fourth, the presence of regulatory components was examined by enzyme-linked immunosorbent assay and by the inhibition of the ability of tears to supplement deficient sera.

RESULTS

Components C1q, C3, factor B, C4, C5, and C9 were detected in closed-eye tears. Only C3, factor B, and C4 were detected in open-eye and reflex tears. Tears were able to supplement complement-deficient sera, indicating that the components were in an active state. Complement components C3, factor B, C4, and C9 were activated in closed-eye tears. The regulatory protein decay-accelerating factor was found only in closed-eye tears. Lactoferrin, another regulatory protein present in all tear types, was shown to inhibit complement-mediated red blood cell lysis, although the inhibition by closed-eye tear lactoferrin was reduced compared to that isolated from other tear types.

CONCLUSIONS

This study has demonstrated that the complement system in tears was functionally active and that the concentration of all components was increased greatly in closed-eye tears. In spite of the presence of regulatory proteins, proteins of the complement cascade in tears were shown to be activated.

The relative abundance of a salivary protein, bSP30, is correlated with susceptibility to bloat in cattle herds selected for high or low bloat susceptibility

Pasture bloat is a serious economic and animal welfare problem in cattle grazed on legumes in New Zealand. Analysis of salivary proteins from dairy cattle in herds bred for either low or high susceptibility to bloat has resulted in the identification of a 30 kilodalton protein, which we term bSP30, whose relative abundance is negatively correlated with bloat score (r = -0.40 +/- 0.12). From 74 animals sampled, relative abundance of bSP30 was 66 +/- 15% higher in the low-susceptibility herd than in the high-susceptibility herd. Relative abundance of bSP30 also varied significantly within individuals, according to feeding or time of day, and from day to day. A sequence homology search of 38 amino acids derived from three tryptic fragments of the protein suggests that the amino acid sequence of bSP30 has not been described previously. Amino acid analysis indicates that bSP30 is not a member of the proline-rich family of salivary proteins. The function of bSP30 is unknown but it is conceivable that it plays a role in the aetiology of bloat.

The effect of eye closure on protein and complement deposition on Group IV hydrogel contact lenses: relationship to tear flow dynamics

PURPOSE

This study was designed to determine the effect of overnight eye closure on the rate and composition of protein deposition on high water content ionic matrix soft contact lenses (Group IV SCLs) and to extrapolate from this data information on the probable change in the rate of reflex-type tear secretion associated with eye closure.

METHODS

Group IV SCLs were temporally sampled after equivalent periods of wear under closed eye (C) or open eye (O) conditions. Lenses were rinsed in saline and the majority of the tightly bound protein extracted at 90 degrees C in 40% urea, containing 1% SDS, 1 mM DTT, 100 mM Tris-HCl (pH 8.00). Residual protein was determined by Coomassie staining of the extracted lenses and densitometric analysis. Extracted protein was quantitated and separated by SDS-PAGE. Gels were either stained with Coomassie blue or reversibly stained with imidazole-zinc and blotted. Blots were PAS stained, or lectin and antibody probed for glycoproteins, secretory IgA (sIgA), IgG, lysozyme and complement C3. Laboratory simulated deposition studies were carried out on unworn lenses exposed to HPLC purified lysozyme.

RESULTS

The protein in the saline rinse, to a large degree mirrored the composition of tear fluid in which the lens had been residing (O or C). This would suggest that the saline wash consists of residual tear fluid and loosely adherent protein. In contrast, the urea extracts were highly homogeneous consisting primarily of lysozyme and to lesser extent lysozyme dimer. This supports the contention that the Group IV SCL functions in the eye much as cationic exchange resin selectively absorbing lysozyme. C extracts also proved relatively enriched in trace amounts of sIgA, IgG and complement C3 and its breakdown products. High levels of C3 and C3 breakdown products were specifically recovered only in the C worn lens extracts from a subject experiencing unilateral contact lens associated corneal infiltrates from the affected eye. In all subjects, markedly less protein (lysozyme) was recovered in urea extracts of lenses exposed to 7-8 h of closed eye as compared to open eye wear (0.20 +/- .08 versus 0.79 +/- .15 mg/lens (n = 6)). Temporal studies further revealed that deposition was linearly related to duration of wear during the initial phase of conditioning film formation giving rise to rate constants for lysozyme deposition of 2.2 +/- 0.29 (n = 5) and 0.20 +/- 0.06 microgram/min (n = 4) under open and closed eye conditions respectively. With further wear, deposition eventually reached a steady state. Under laboratory conditions, lysozyme was much rapidly and quantitatively removed from solution in a manner following a hyperbolic plot. This suggests that during the initial phase of deposition the rate of deposition is limited by the capacity of the tear fluid to deliver lysozyme to the lens surface under these two extremes of conditions.

CONCLUSIONS

Eye closure profoundly affects the rate of lysozyme deposition on Group IV hydrogels and the composition of minor biofilm constituents in a manner that could affect biocompatibility. Findings support the contention that eye closure results in a > 90% reduction in the rate of reflex-type tear secretion.

Phenotypic markers for selection of nematode-resistant sheep

Nematode-resistance of an animal can be defined as an enhanced natural ability, relative to its peers, to both prevent establishment of larval nematodes and evict any that do establish. These parameters are not measurable in a practical sense and consequently nematode-resistance has usually been defined in terms of low faecal nematode egg counts (FEC). Studies in New Zealand and Australia have demonstrated that nematode-resistance, as measured by FEC, has a heritability of about 0.3 in Romney and Merino sheep. However as a selection trait FEC has practical limitations and its use may incur production penalties through withholding drench treatment for prolonged periods or from a need for artificial challenge. FEC is influenced by the level and composition of a natural nematode challenge and especially the expression of the immune response. Thus immunological parameters which reflect the underlying genetic resistance could potentially be used as phenotypic markers. Ideally, a useful phenotypic marker would be easy to sample and its assay would be inexpensive and able to be automated, in addition to being strongly correlated with nematode-resistance. Results from several New Zealand trials have indicated that antibody levels (particularly IgG1) to excretory/secretory antigens of L3 nematodes such as Trichostrongylus colubriformis may meet these criteria. Levels of antibody against L3 antigens are also independent of on-farm drenching strategies. Blood eosinophil count has also been considered for use as a selection parameter but a high degree of sample variability reduces its potential. Other immunological parameters associated with nematode-resistance which have potential as phenotypic markers include serum nematode-specific IgE and products of mucosal mast cells such as proteinases. It is likely that as the critical immune responses of sheep to nematodes become more clearly defined, new immunological parameters with potential for use as phenotypic markers will be found. The definition of these immune responses will also assist in the identification and characterization of genetic markers.

Feasibility and implications of breeding sheep for resilience to nematode challenge

There are potentially 2 different types of host response which could be targeted when seeking to breed sheep which require minimal frequency of anthelmintic treatment to maintain acceptable health and productivity in the face of nematode challenge. These are "resistance" (the ability to suppress the establishment and/or subsequent development of a parasite infection), and "resilience" (the ability to maintain relatively undepressed production while subjected to parasite challenge). Most studies have concentrated on resistance, and used faecal worm egg count (FEC) as the selection criterion. However, in Romney sheep in New Zealand, it has become apparent that "resistance to infection" does not equate to "disease resistance" in the strict sense. Although genetically low FEC Romney lambs have been shown to have significantly reduced burdens of the most important nematode species, they nevertheless appear to have no significant production advantages over their higher FEC counterparts when all are grazed together under the same larval challenge. Furthermore there is evidence of an unfavourable association between FEC and dagginess (soiling of the breech area) suggesting that some forms of host response to nematode challenge may result in diarrhoea. Our results suggest that the main benefits of selectively breeding for low FEC are likely to be derived indirectly as a result of reduced pasture contamination. This has led us to investigate resilience as a possible alternative breeding option to resistance. Over a period of 3 years approximately 14,000 progeny of 213 different rams were tested for resilience (assessed in terms of drench requirements using an individual "on demand" treatment procedure), as well as growth rate, dag-score, FEC and fleece-weight. Overall the heritabilities of various measures of resilience examined proved to be relatively low (ranging between 0.10 +/- 0.03 and 0.19 +/- 0.04), although estimates varied between flocks and years possibly as a result of differences in the severity of challenge. Nevertheless, results suggested that progeny-test selection for resilience would lead to lambs with higher growth rates and lower dags-scores when left undrenched on infective pasture. In contrast to some Australian results we found no positive association between resilience to mematode challenge and resistance to infection. If the potential benefits of both resistance and resilience are to be captured our results suggest that an index selection procedure will be needed.

LIM-kinase1 hemizygosity implicated in impaired visuospatial constructive cognition

To identify genes important for human cognitive development, we studied Williams syndrome (WS), a developmental disorder that includes poor visuospatial constructive cognition. Here we describe two families with a partial WS phenotype; affected members have the specific WS cognitive profile and vascular disease, but lack other WS features. Submicroscopic chromosome 7q11.23 deletions cosegregate with this phenotype in both families. DNA sequence analyses of the region affected by the smallest deletion (83.6 kb) revealed two genes, elastin (ELN) and LIM-kinase1 (LIMK1). The latter encodes a novel protein kinase with LIM domains and is strongly expressed in the brain. Because ELN mutations cause vascular disease but not cognitive abnormalities, these data implicate LIMK1 hemizygosity in imparied visuospatial constructive cognition.