| 2011. |
- Powers, Christopher, et al.
(författare)
-
Two canonically aerobic foraminifera express distinct peroxisomal and mitochondrial metabolisms
- 2022
-
Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Certain benthic foraminifera thrive in marine sediments with low or undetectable oxygen. Potential survival avenues used by these supposedly aerobic protists include fermentation and anaerobic respiration, although details on their adaptive mechanisms remain elusive. To better understand the metabolic versatility of foraminifera, we studied two benthic species that thrive in oxygen-depleted marine sediments. Here we detail, via transcriptomics and metatranscriptomics, differential gene expression of Nonionella stella and Bolivina argentea, collected from Santa Barbara Basin, California, USA, in response to varied oxygenation and chemical amendments. Organelle-specific metabolic reconstructions revealed these two species utilize adaptable mitochondrial and peroxisomal metabolism. N. stella, most abundant in anoxia and characterized by lack of food vacuoles and abundance of intracellular lipid droplets, was predicted to couple the putative peroxisomal beta-oxidation and glyoxylate cycle with a versatile electron transport system and a partial TCA cycle. In contrast, B. argentea, most abundant in hypoxia and contains food vacuoles, was predicted to utilize the putative peroxisomal gluconeogenesis and a full TCA cycle but lacks the expression of key beta-oxidation and glyoxylate cycle genes. These metabolic adaptations likely confer ecological success while encountering deoxygenation and expand our understanding of metabolic modifications and interactions between mitochondria and peroxisomes in protists.
|
|
| 2012. |
- Pradhan, Ajay, 1983-, et al.
(författare)
-
Activation of NF-kappa B Protein Prevents the Transition from Juvenile Ovary to Testis and Promotes Ovarian Development in Zebrafish
- 2012
-
Ingår i: Journal of Biological Chemistry. - : The American Society for Biochemistry and Molecular Biology. - 0021-9258 .- 1083-351X. ; 287:45, s. 37926-37938
-
Tidskriftsartikel (refereegranskat)abstract
- Testis differentiation in zebrafish involves juvenile ovary to testis transformation initiated by an apoptotic wave. The molecular regulation of this transformation process is not fully understood. NF-kappa B is activated at an early stage of development and has been shown to interact with steroidogenic factor-1 in mammals, leading to the suppression of anti-Mullerian hormone (Amh) gene expression. Because steroidogenic factor-1 and Amh are important for proper testis development, NF-kappa B-mediated induction of anti-apoptotic genes could, therefore, also play a role in zebrafish gonad differentiation. The aim of this study was to examine the potential role of NF-kappa B in zebrafish gonad differentiation. Exposure of juvenile zebrafish to heat-killed Escherichia coli activated the NF-kappa B pathways and resulted in an increased ratio of females from 30 to 85%. Microarray and quantitative real-time-PCR analysis of gonads showed elevated expression of NF-kappa B-regulated genes. To confirm the involvement of NF-kappa B-induced anti-apoptotic effects, zebrafish were treated with sodium deoxycholate, a known inducer of NF-kappa B or NF-kappa B activation inhibitor (NAI). Sodium deoxycholate treatment mimicked the effect of heat-killed bacteria and resulted in an increased proportion of females from 25 to 45%, whereas the inhibition of NF-kappa B using NAI resulted in a decrease in females from 45 to 20%. This study provides proof for an essential role of NF-kappa B in gonadal differentiation of zebrafish and represents an important step toward the complete understanding of the complicated process of sex differentiation in this species and possibly other cyprinid teleosts as well.
|
|
| 2013. |
- Prokunina-Olsson, Ludmila, et al.
(författare)
-
Tissue-specific alternative splicing of TCF7L2
- 2009
-
Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 18:20, s. 3795-3804
-
Tidskriftsartikel (refereegranskat)abstract
- Common variants in the transcription factor 7-like 2 (TCF7L2) gene have been identified as the strongest genetic risk factors for type 2 diabetes (T2D). However, the mechanisms by which these non-coding variants increase risk for T2D are not well-established. We used 13 expression assays to survey mRNA expression of multiple TCF7L2 splicing forms in up to 380 samples from eight types of human tissue (pancreas, pancreatic islets, colon, liver, monocytes, skeletal muscle, subcutaneous adipose tissue and lymphoblastoid cell lines) and observed a tissue-specific pattern of alternative splicing. We tested whether the expression of TCF7L2 splicing forms was associated with single nucleotide polymorphisms (SNPs), rs7903146 and rs12255372, located within introns 3 and 4 of the gene and most strongly associated with T2D. Expression of two splicing forms was lower in pancreatic islets with increasing counts of T2D-associated alleles of the SNPs: a ubiquitous splicing form (P = 0.018 for rs7903146 and P = 0.020 for rs12255372) and a splicing form found in pancreatic islets, pancreas and colon but not in other tissues tested here (P = 0.009 for rs12255372 and P = 0.053 for rs7903146). Expression of this form in glucose-stimulated pancreatic islets correlated with expression of proinsulin (r(2) = 0.84-0.90, P < 0.00063). In summary, we identified a tissue-specific pattern of alternative splicing of TCF7L2. After adjustment for multiple tests, no association between expression of TCF7L2 in eight types of human tissue samples and T2D-associated genetic variants remained significant. Alternative splicing of TCF7L2 in pancreatic islets warrants future studies. GenBank Accession Numbers: FJ010164-FJ010174.
|
|
| 2014. |
- Pruszynski, J Andrew, et al.
(författare)
-
Goal-dependent modulation of fast feedback responses in primary motor cortex
- 2014
-
Ingår i: Journal of Neuroscience. - : Society for neuroscience. - 0270-6474 .- 1529-2401. ; 34:13, s. 4608-4617
-
Tidskriftsartikel (refereegranskat)abstract
- Many human studies have demonstrated that rapid motor responses (i.e., muscle-stretch reflexes) to mechanical perturbations can be modified by a participant's intended response. Here, we used a novel experimental paradigm to investigate the neural mechanisms that underlie such goal-dependent modulation. Two monkeys positioned their hand in a central area against a constant load and responded to mechanical perturbations by quickly placing their hand into visually defined spatial targets. The perturbation was chosen to excite a particular proximal arm muscle or isolated neuron in primary motor cortex and two targets were placed so that the hand was pushed away from one target (OUT target) and toward the other (IN target). We chose these targets because they produced behavioral responses analogous to the classical verbal instructions used in human studies. A third centrally located target was used to examine responses with a constant goal. Arm muscles and neurons robustly responded to the perturbation and showed clear goal-dependent responses ∼35 and 70 ms after perturbation onset, respectively. Most M1 neurons and all muscles displayed larger perturbation-related responses for the OUT target than the IN target. However, a substantial number of M1 neurons showed more complex patterns of target-dependent modulation not seen in muscles, including greater activity for the IN target than the OUT target, and changes in target preference over time. Together, our results reveal complex goal-dependent modulation of fast feedback responses in M1 that are present early enough to account for goal-dependent stretch responses in arm muscles.
|
|
| 2015. |
- Pruszynski, J. Andrew, et al.
(författare)
-
Optimal feedback control and the long-latency stretch response
- 2012
-
Ingår i: Experimental Brain Research. - : Springer Science and Business Media LLC. - 0014-4819 .- 1432-1106. ; 218:3, s. 341-359
-
Forskningsöversikt (refereegranskat)abstract
- There has traditionally been a separation between voluntary control processes and the fast feedback responses which follow mechanical perturbations (i.e., stretch "reflexes"). However, a recent theory of motor control, based on optimal control, suggests that voluntary motor behavior involves the sophisticated manipulation of sensory feedback. We have recently proposed that one implication of this theory is that the long-latency stretch "reflex", like voluntary control, should support a rich assortment of behaviors because these two processes are intimately linked through shared neural circuitry including primary motor cortex. In this review, we first describe the basic principles of optimal feedback control related to voluntary motor behavior. We then explore the functional properties of upper-limb stretch responses, with a focus on how the sophistication of the long-latency stretch response rivals voluntary control. And last, we describe the neural circuitry that underlies the long-latency stretch response and detail the evidence that primary motor cortex participates in sophisticated feedback responses to mechanical perturbations.
|
|
| 2016. |
- Pruszynski, J. Andrew, et al.
(författare)
-
Primary motor cortex underlies multi-joint integration for fast feedback control
- 2011
-
Ingår i: Nature. - London : Macmillan Journals. - 0028-0836 .- 1476-4687. ; 478:7369, s. 387-390
-
Tidskriftsartikel (refereegranskat)abstract
- A basic difficulty for the nervous system is integrating locally ambiguous sensory information to form accurate perceptions about the outside world(1-4). This local-to-global problem is also fundamental to motor control of the arm, because complex mechanical interactions between shoulder and elbow allow a particular amount of motion at one joint to arise from an infinite combination of shoulder and elbow torques(5). Here we show, in humans and rhesus monkeys, that a transcortical pathway through primary motor cortex (M1) resolves this ambiguity during fast feedback control. We demonstrate that single M1 neurons of behaving monkeys can integrate shoulder and elbow motion information into motor commands that appropriately counter the underlying torque within about 50 milliseconds of a mechanical perturbation. Moreover, we reveal a causal link between M1 processing and multi-joint integration in humans by showing that shoulder muscle responses occurring 50 milliseconds after pure elbow displacement can be potentiated by transcranial magnetic stimulation. Taken together, our results show that transcortical processing through M1 permits feedback responses to express a level of sophistication that rivals voluntary control; this provides neurophysiological support for influential theories positing that voluntary movement is generated by the intelligent manipulation of sensory feedback(6,7).
|
|
| 2017. |
|
|
| 2018. |
- Rahlff, Janina, et al.
(författare)
-
Blue pigmentation of neustonic copepods benefits exploitation of a prey-rich niche at the air-sea boundary
- 2018
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- The sea-surface microlayer (SML) at the air-sea interface is a distinct, under-studied habitat compared to the subsurface and copepods, important components of ocean food webs, have developed key adaptations to exploit this niche. By using automated SML sampling, high-throughput sequencing and unmanned aerial vehicles, we report on the distribution and abundance of pontellid copepods in relation to the unique biophysicochemical signature of the SML. We found copepods in the SML even during high exposure to sun-derived ultraviolet radiation and their abundance was significantly correlated to increased algal biomass. We additionally investigated the significance of the pontellids’ blue pigmentation and found that the reflectance peak of the blue pigment matched the water-leaving spectral radiance of the ocean surface. This feature could reduce high visibility at the air-sea boundary and potentially provide camouflage of copepods from their predators.
|
|
| 2019. |
- Reilly, Colin, et al.
(författare)
-
Autism, ADHD and parent-reported behavioural difficulties in young children with epilepsy
- 2019
-
Ingår i: Seizure. - : Elsevier BV. - 1059-1311 .- 1532-2688. ; 71, s. 233-239
-
Tidskriftsartikel (refereegranskat)abstract
- © 2019 British Epilepsy Association Purpose: To provide data on the prevalence of Autism Spectrum Disorder (ASD), Attention-Deficit/Hyperactivity Disorder (ADHD), and parent reported behaviour difficulties in young children with epilepsy, and to compare results with children with neurodisability (neurodevelopmental/neurological difficulties) without epilepsy. Method: Children with epilepsy (1–7 years, n = 48) and children with neurodisability (1–7 years, n = 48) matched for gender, chronological and developmental age underwent psychological assessment. Parents completed measures of behaviour including the Strengths and Difficulties Questionnaire (SDQ). DSM-5 diagnoses of ASD and ADHD were made at consensus case conferences. Factors associated with child behaviour were analysed using linear regression. Results: Of the children with epilepsy, 18% met ASD criteria and 40% met ADHD criteria (corresponding figures in the non-epilepsy group were 41% and 27%). A large proportion (76%–78%) in both groups scored in the at-risk range on the SDQ and frequently had difficulties across multiple behavioural domains. Children with epilepsy had more concerns expressed regarding attention and mood. None of the epilepsy factors were significantly associated with scores on the behavioural measures. Significance: Young children with epilepsy had a very high level of parent reported behavioural difficulties and a high risk for ADHD and ASD highlighting the need for comprehensive multidisciplinary assessment. Behavioural concerns were not greater than for other children with non-epilepsy related neurodisability with the exception of attention and mood. Epilepsy related factors were not associated with child behaviour, suggesting that seizures per se do not confer a unique risk for behavioural difficulties.
|
|
| 2020. |
- Reilly, Colin, et al.
(författare)
-
Child and parental sleep in young children with epilepsy: A population-based case-control study.
- 2018
-
Ingår i: Epilepsia open. - : Wiley. - 2470-9239. ; 3:3, s. 383-391
-
Tidskriftsartikel (refereegranskat)abstract
- To determine the prevalence of parent-reported sleep problems in young children with epilepsy and their parents, and to compare findings with those in a non-epilepsy-related neurodisability (neurodevelopmental/neurological difficulties) group.Parents of young children (1-7years) with epilepsy (n=48 [91% ascertainment]) completed the Child Sleep Habits Questionnaire (CSHQ). Parents (mothers and fathers) also completed the Pittsburgh Sleep Quality Index (PSQI) and the Iowa Fatigue Scale (IFS) in relation to their own functioning. The responses of parents of children with epilepsy were compared with parents of developmental-, age-, and gender-matched children with nonepilepsy-related neurodisability (n=48).There was not a significant difference in the proportion of children with epilepsy and the children with neurodisability scoring in the at-risk range on the CSHQ (81% vs. 71% respectively) (p=0.232). 62% of mothers and 44% of fathers of children with epilepsy had 'poor quality sleep' on the PSQI; there was not a significant difference between mothers of children with epilepsy and those of children with neurodisability (p=0.526) or IFS (p=0.245) total scores. However, mothers of children with epilepsy had significantly more difficulties on the productivity subscale of the IFS (p=0.004). There were no significant differences between fathers' scores on either measure. In the epilepsy group, child behavioral problems (p=0.001) were independently associated with child sleep difficulties and maternal mental health problems were associated with parental sleep difficulties (p=0.04) and fatigue (p=0.018).Young children with epilepsy and their parents have a high rate of sleep difficulties. There is a need to develop effective interventions for this population, taking into consideration of the role of child behavioral problems and parental mental health difficulties.
|
|
