The effects of hypoxia on zooplankton population estimates and migration in lakes

Many zooplankton species typically exhibit diel vertical migration (DVM), where zooplankton migrate from the hypolimnion to the epilimnion of lakes at night. Zooplankton exhibit this behavior to avoid visual predators and UV radiation by remaining in the bottom waters during the day and ascending to the surface waters to feed on phytoplankton at night. However, hypoxic conditions in the hypolimnion of lakes mayinterfere with DVM and force zooplankton to increase diel horizontal migration (DHM) to find predation refuge in littoral zones. Climate change and eutrophication are expected to increase the prevalence and severity of hypoxic conditions worldwide and thereby possibly alter zooplankton migration patterns. We hypothesize that hypoxia will force zooplankton to shift their migration patterns from predominantly DVM to DHM to avoid oxygen-depleted bottom waters. To test our hypothesis, we are conducting a standardized global sampling program to test whether pelagic, full water column estimates of zooplankton are greater at night versus the day under hypolimnetic hypoxic versus oxic conditions. Participants are aiming to sample at least one lake with an oxic hypolimnion and one lake with a hypoxic hypolimnion during the thermally-stratified period at midday and midnight. With our global dataset (currently expecting about 60 lakes in 22 countries), our goal is to improve our understanding of how global change may alter zooplankton migration behavior and patterns in lakes.info:eu-repo/semantics/publishedVersio

Slaughter weight rather than sex affects carcass cuts and tissue composition of Bisaro pigs

Carcass cuts and tissue composition were assessed in Bisaro pigs (n=64) from two sexes (31 gilts and 33 entire males) reared until three target slaughter body-weights (BW) means: 17 kg, 32 kg, and 79 kg. Dressing percentage and backfat thickness increased whereas carcass shrinkage decreased with increasing BW. Slaughter weight affected most of the carcass cut proportions, except shoulder and thoracic regions. Bone proportion decreased linearly with increasing slaughter BW, while intermuscular and subcutaneous adipose tissue depots increased concomitantly. Slaughter weight increased the subcutaneous adipose tissue proportion but this impaired intramuscular and intermuscular adipose tissues in the loin primal. The sex of the pigs minimally affected the carcass composition, as only the belly weight and the subcutaneous adipose tissue proportions were greater in gilts than in entire males. Light pigs regardless of sex are recommended to balance the trade-offs between carcass cuts and their non-edible compositional outcomes.Work included in the Portuguese PRODER research Project BISOPORC – Pork extensive production of Bísara breed, in two alternative systems: fattening on concentrate vs chesnut, Project PRODER SI I&DT Medida 4.1 “Cooperação para a Inovação”. The authors are grateful to Laboratory of Carcass and Meat Quality of Agriculture School of Polytechnic Institute of Bragança ‘Cantinho do Alfredo’. The authors are members of the MARCARNE network, funded by CYTED (ref. 116RT0503).info:eu-repo/semantics/publishedVersio

Prenatal diagnosis of methymalonic aciduria and homocystinuria cblC type using DNA analysis

Methylmalonic aciduria (MMA) and homocystinuria, cblC type is the most frequent inborn error of vitamin B12. CblC patients present with a heterogeneous clinical picture. To date, the early prenatal diagnosis of MMA and homocystinuria, cblC type is performed by determination of methylmalonic acid and total homocysteine (Hcy) in amniotic fluid supernatant. In this paper we report a case of prenatal diagnosis, using genetic analysis, of MMA and homocystinuria, cblC type in an at risk couple. Direct sequencing analysis of the amplified products of chorionic villi biopsy extracted DNA showed normal sequence in the fetal DNA. Mutation analysis of the MMACHC gene is more cost-effective and less time-consuming than the biochemical approach. Early prenatal treatment may have an impact on the long-term complications associated with cblC disease. Future studies with the aim of determining the long-term benefits of daily parenteral OHCbl started soon after conception in at risk mothers should be considered. In this context early prenatal diagnosis could determine whether therapy needs to be continued

Wilson's disease caused by alternative splicing and Alu exonization due to a homozygous 3039-bp deletion spanning from intron 1 to exon 2 of the ATP7B gene

We describe a case of Wilson's disease (WD) diagnosed at 5 years after routine biochemical test showed increased aminotransferases. Mutation analysis of the ATP7B gene revealed a 3039-bp deletion in the homozygous state spanning from the terminal part of intron 1 to nt position 368 of exon 2. This deletion results in the activation of 3 cryptic splice sites: an AG acceptor splice site in nt positions 578-579 producing a different breakpoint and removing the first 577 nts of exon 2, an acceptor and a donor splice site in nt positions 20363-4 and 20456-7, respectively, in intron 1, resulting in the activation of a 94-bp cryptic Alu exon being incorporated into the mature transcript. The resulting alternative transcript contains a TAG stop codon in the first amino acid position of the cryptic exon, likely producing a truncated, non-functional protein. This study shows that intron exonization can also occur in humans through naturally occurring gross deletions. The results suggest that the combination of DNA and RNA analyses can be used for molecular characterization of gross ATP7B deletions, thus improving genetic counseling and diagnosis of WD. Moreover these studies help to better establish new molecular mechanisms producing Wilson's disease

“Acquired” hepatocerebral degeneration in a patient heterozygote carrier for a novel mutation in <i>ATP7B</i> gene

Acquired hepatocerebral degeneration (AHD) is a rare type of hepatic encephalopathy characterized by neuropsychiatric symptomatology, and peculiar neuroradiologic findings, without the clinical evidence of Wilson’s disease (WD). We studied a patient with AHD responsive to penicillamine who was heterozygote carrier for a novel mutation in the ATP7B gene, and discussed the possible role of the mutation in facilitating the appearance of the syndrome. A 37-year-old man with liver cirrhosis related to chronic hepatitis C was admitted because of progressive consciousness impairment. Family history was negative for WD. Ammoniemia was 176 lmol/L (NR, 9–33 lmol/L); total bilirubin 1.71 mg/dL (NR, 0.2–1.3 mg/dL); serum albumin 2.6 g/dL (NR, 3.3–5 g/dL); AST 62 U/L (NR, 10–45 U/L). Electroencephalogram disclosed diffuse slow wave activity. After rifaximin, lactulose, and branched chain amino acid infusion, his arousal state went back normal in about 12 hours, and ammonia levels decreased to 94 lmol/L

RNA analysis of consensus sequence splicing mutations: implications for the diagnosis of Wilson disease

Wilson disease (WD) is an autosomal recessive disorder caused by a defective function of the copper-transporting ATP7B protein. This results in progressive copper overload and consequent liver, brain, and kidney damage. Approximately 300 WD-causing mutations have been described to date. Missense mutations are largely prevalent, while splice-site mutations are rarer. Of these, only a minority are detected in splicing consensus sequences. Further, few splicing mutations have been studied at the RNA level. In this study we report the RNA molecular characterization of three consensus splice-site mutations identified by DNA analysis in WD patients. One of them, c.51 + 4 A --> T, resides in the consensus sequence of the donor splice site of intron 1; the second, c. 2121 + 3 A --> G, occurred in position + 3 of intron 7; and the c.2447 + 5 G --> A is localized in the consensus sequence of the donor splice site of intron 9. Analysis revealed predominantly abnormal splicing in the samples carrying mutations compared to the normal controls. These results strongly suggest that consensus sequence splice-site mutations result in disease by interfering with the production of the normal WD protein. Our data contribute to understanding the mutational spectrum that affect splicing and improve our capability in WD diagnosis

Twenty-four novel mutations in Wilson disease patients of predominantly Italian origin

Herein we report the results of mutation analysis of the ATP7B gene in a group of 134 Wilson disease (WD) families (268 chromosomes) prevalently of Italian origin. Using the SSCP and sequencing methods we identified 71 disease-causing mutations. Twenty-four were novel, while 19 more mutations already described, were identified in new populations in this study. A known mutation G591D showed a regional distribution, since it was only detected in 38.5% of the analyzed chromosomes in WD patients originating from Apulia, a region of South Italy. Detection of new mutations in the ATP7B gene increases our capability of molecular analysis that is essential for early diagnosis and treatment of WD

The Canine copper toxicosis gene <i>MURR1</i> is not implicated in the pathogenesis of Wilson disease

Background It has recently been demonstrated that the Wilson disease (WD) protein directly interacts with the human homolog of the MURR1 protein in vitro and in vivo, and that this interaction is specific for the copper transporter. The aim of the present study was to clarify the role of MURR1 in the pathogenesis of WD as well as in other WD-like disorders of hepatic copper metabolism of unknown origin. Methods Using the single-strand conformation polymorphism (SSCP) method followed by sequencing, we analyzed the 5′ untranslated region (UTR) and three exons of the MURR1 gene in three groups of patients: 19 wd patients in whom no mutations were detected in the ATP7B gene, 53 wd patients in whom only one mutation in the ATP7B gene was found, and 34 patients in whom clinical and laboratory data suggested a WD-like disorder of hepatic copper metabolism of unknown origin. Results We  detected in these patients six rare nucleotide substitutions, namely one splice-site consensus sequence and one missense and four silent nucleotide substitutions. All substitutions except one were found in the heterozygous state. No difference in the frequencies of the various substitutions was observed between patients and controls. Conclusions These data suggest that the MURR1 gene and its protein product are unlikely to play a primary role in the pathogenesis of Wilson disease. More extensive studies with larger numbers of clinically homogeneous patients should be carried out to establish whether nucleotide alterations in the MURR1 gene may have a role in causing WD or WD-like disorders or act as modifying factors in the phenotype variability in WD.</br