Generation of immortalized human endometrial stromal cell lines with different endometriosis risk genotypes.

Endometriotic lesions are composed in part of endometrial-like stromal cells, however, there is a shortage of immortalized human endometrial stromal cultures available for research. As genetic factors play a role in endometriosis risk, it is important that genotype is also incorporated into analysis of pathological mechanisms. Human telomerase reverse transcriptase (hTERT) immortalization (using Lenti-hTERT-green fluorescent protein virus) took place following genotype selection; 13 patients homozygous for either the risk or non-risk 'other' allele for one or more important endometriosis risk single nucleotide polymorphism on chromosome 1p36.12 (rs3820282, rs56318008, rs55938609, rs12037376, rs7521902 or rs12061255). Short tandem repeat DNA profiling validated that donor tissue matched that of the immortalized cell lines and confirmed that cultures were genetically novel. Expression of morphological markers (vimentin and cytokeratin) and key genes of interest (telomerase, estrogen and progesterone receptors and LINC00339) were examined and functional assays for cell proliferation, steroid hormone and inflammatory responses were performed for 7/13 cultures. All endometrial stromal cell lines maintained their fibroblast-like morphology (vimentin-positive) and homozygous endometriosis-risk genotype following introduction of hTERT. Furthermore, the new stromal cultures demonstrated positive and diverse responses to hormones (proliferation and decidualisation changes) and inflammation (dose-dependent response), while maintaining hormone receptor expression. In conclusion, we successfully developed a range of human endometrial stromal cell lines that carry important endometriosis-risk alleles. The wider implications of this approach go beyond advancing endometriosis research; these cell lines will be valuable tools for multiple endometrial pathologies offering a level of genetic and phenotypic diversity not previously available.

Exercise in an animal model of Parkinson's disease: Motor recovery but not restoration of the nigrostriatal pathway.

Many clinical studies have reported on the benefits of exercise therapy in patients with Parkinson's disease (PD). Exercise cannot stop the progression of PD or facilitate the recovery of dopamine (DA) neurons in the substantia nigra pars compacta (SNpc) (Bega et al., 2014). To tease apart this paradox, we utilized a progressive MPTP (1-methyl-4-phenyl-1,2,3,6-tetra-hydropyridine) mouse model in which we initiated 4weeks of treadmill exercise after the completion of toxin administration (i.e., restoration). We found in our MPTP/exercise (MPTP+EX) group several measures of gait function that recovered compared to the MPTP only group. Although there was a small recovery of tyrosine hydroxylase (TH) positive DA neurons in the SNpc and terminals in the striatum, this increase was not statistically significant. These small changes in TH could not explain the improvement of motor function. The MPTP group had a significant 170% increase in the glycosylated/non-glycosylated dopamine transporter (DAT) and a 200% increase in microglial marker, IBA-1, in the striatum. The MPTP+EX group showed a nearly full recovery of these markers back to the vehicle levels. There was an increase in GLT-1 levels in the striatum due to exercise, with no change in striatal BDNF protein expression. Our data suggest that motor recovery was not prompted by any significant restoration of DA neurons or terminals, but rather the recovery of DAT and dampening the inflammatory response. Although exercise does not promote recovery of nigrostriatal DA, it should be used in conjunction with pharmaceutical methods for controlling PD symptoms.

CNS-specific regulatory elements in brain-derived HIV-1 strains affect responses to latency-reversing agents with implications for cure strategies.

Latency-reversing agents (LRAs), including histone deacetylase inhibitors (HDACi), are being investigated as a strategy to eliminate latency in HIV-infected patients on suppressive antiretroviral therapy. The effectiveness of LRAs in activating latent infection in HIV strains derived from the central nervous system (CNS) is unknown. Here we show that CNS-derived HIV-1 strains possess polymorphisms within and surrounding the Sp transcription factor motifs in the long terminal repeat (LTR). These polymorphisms result in decreased ability of the transcription factor specificity protein 1 to bind CNS-derived LTRs, reducing the transcriptional activity of CNS-derived viruses. These mutations result in CNS-derived viruses being less responsive to activation by the HDACi panobinostat and romidepsin compared with lymphoid-derived viruses from the same subjects. Our findings suggest that HIV-1 strains residing in the CNS have unique transcriptional regulatory mechanisms, which impact the regulation of latency, the consideration of which is essential for the development of HIV-1 eradication strategies.

The evolution of aquatic feeding in seals: insights from Enaliarctos (Carnivora: Pinnipedimorpha), the oldest known seal.

The development of pierce-feeding and loss of oral processing represented major adaptations for underwater feeding in marine mammals. We examined the evolution of pierce-feeding and its association with changes in tooth spacing and tooth size to determine whether pierce-feeding was practiced by the earliest known pinnipeds. Data on crown size and spacing in postcanine dentition were collected and 1) analysed by principal components analysis (PCA) to determine the tooth morphospace of arctoid carnivores, 2) analysed by least squares (LS) regression and phylogenetic independent contrasts (PIC) to determine what morphological variables were associated with increases in tooth spacing, and 3) used to reconstruct the evolution of feeding related traits within a phylogenetic context. The PCA analysis revealed that within arctoid carnivores, the greatest differences in morphospace were associated with pierce-feeding, and the early-diverging seal Enaliarctos was placed within the pinniped morphospace. Increased tooth spacing within Pinnipedia is a result of decreased postcanine crown size. When the evolution of dental characters is reconstructed, 'enaliarctines' were found to represent an intermediate stage in evolution between 'fissiped' and pinniped carnivores. They retained the limited tooth spacing of terrestrial carnivores, possessed postcanine crown lengths intermediate in size between pinnipeds and fissipeds, and possessed reduced heterodonty characteristic of crown pinnipeds. Our study indicated that pierce-feeding evolved early within pinnipeds. This suggested either that pierce-feeding evolved prior to the loss of mastication, or that pierce-feeding evolved at the same time as loss of mastication, and well before simplification of the dentition was completed.

Two high-mobility group box domains act together to underwind and kink DNA.

High-mobility group protein 1 (HMGB1) is an essential and ubiquitous DNA architectural factor that influences a myriad of cellular processes. HMGB1 contains two DNA-binding domains, box A and box B, which have little sequence specificity but have remarkable abilities to underwind and bend DNA. Although HMGB1 box A is thought to be responsible for the majority of HMGB1-DNA interactions with pre-bent or kinked DNA, little is known about how it recognizes unmodified DNA. Here, the crystal structure of HMGB1 box A bound to an AT-rich DNA fragment is reported at a resolution of 2 Å. Two box A domains of HMGB1 collaborate in an unusual configuration in which the Phe37 residues of both domains stack together and intercalate the same CG base pair, generating highly kinked DNA. This represents a novel mode of DNA recognition for HMGB proteins and reveals a mechanism by which structure-specific HMG boxes kink linear DNA.

Intervention with exercise restores motor deficits but not nigrostriatal loss in a progressive MPTP mouse model of Parkinson's disease.

Many studies have investigated exercise therapy in Parkinson's disease (PD) and have shown benefits in improving motor deficits. However, exercise does not slow down the progression of the disease or induce the revival of lost nigrostriatal neurons. To examine the dichotomy of behavioral improvement without the slowing or recovery of dopaminergic cell or terminal loss, we tested exercise therapy in an intervention paradigm where voluntary running wheels were installed half-way through our progressive PD mouse model. In our model, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is administered over 4 weeks with increased doses each week (8, 16, 24, 32-kg/mg). We found that after 4 weeks of MPTP treatment, mice that volunteered to exercise had behavioral recovery in several measures despite the loss of 73% and 53% tyrosine hydroxylase (TH) within the dorsolateral (DL) striatum and the substantia nigra (SN), respectively which was equivalent to the loss seen in the mice that did not exercise but were also administered MPTP for 4 weeks. Mice treated with 4 weeks of MPTP showed a 41% loss of vesicular monoamine transporter II (VMAT2), a 71% increase in the ratio of glycosylated/non-glycosylated dopamine transporter (DAT), and significant increases in glutamate transporters including VGLUT1, GLT-1, and excitatory amino acid carrier 1. MPTP mice that exercised showed recovery of all these biomarkers back to the levels seen in the vehicle group and showed less inflammation compared to the mice treated with MPTP for 4 weeks. Even though we did not measure tissue dopamine (DA) concentration, our data suggest that exercise does not alleviate motor deficits by sparing nigrostriatal neurons, but perhaps by stabilizing the extraneuronal neurotransmitters, as evident by a recovery of DA and glutamate transporters. However, suppressing inflammation could be another mechanism of this locomotor recovery. Although exercise will not be a successful treatment alone, it could supplement other pharmaceutical approaches to PD therapy.

HIV eradication symposium: will the brain be left behind?

On 18 July 2014, the National Institute of Mental Health in collaboration with ViiV Health Care and Boehringer Ingelheim supported a symposium on HIV eradication and what it meant for the brain. The symposium was an affiliated event to the 20th International AIDS Conference. The meeting was held in Melbourne, Australia, and brought together investigators currently working on HIV eradication together with investigators who are working on the neurological complications of HIV. The purpose of the meeting was to bring the two fields of HIV eradication and HIV neurology together to foster dialogue and cross talk to move the eradication field forward in the context of issues relating to the brain as a potential reservoir of HIV. The outcomes of the symposium were that there was substantive but not definitive evidence for the brain as an HIV reservoir that will provide a challenge to HIV eradication. Secondly, the brain as a clinically significant reservoir for HIV is not necessarily present in all patients. Consequently, there is an urgent need for the development of biomarkers to identify and quantify the HIV reservoir in the brain. Lastly, when designing and developing eradication strategies, it is critical that approaches to target the brain reservoir be included.

Intervention with 7,8-dihydroxyflavone blocks further striatal terminal loss and restores motor deficits in a progressive mouse model of Parkinson's disease.

Parkinson's disease (PD) is a progressive neurological disorder and current therapies help alleviate symptoms, but are not disease modifying. In the flavonoid class of compounds, 7,8-dihydroxyflavone (7,8-DHF) has been reported to elicit tyrosine kinase receptor B (TrkB) dimerization and autophosphorylation that further stimulates signaling cascades to promote cell survival/growth, differentiation, and plasticity. In this study we investigated if 7,8-DHF could prevent further loss of dopaminergic cells and terminals if introduced at the midpoint (i.e. intervention) of our progressive mouse model of PD. In our model, 1-methyl-4phenyl-1,2,3,6-tetrahyrdopyridine (MPTP) is administered with increased doses each week (8, 16, 24, 32-kg/mg) over a 4-week period. We found that despite 4 weeks of MPTP treatment, animals administered 7,8-DHF starting at the 2-week time period maintained 54% of the tyrosine hydroxylase (TH) levels within the dorsolateral (DL) striatum compared to the vehicle group, which was comparable to animals treated with MPTP for 2 weeks and was significantly greater compared to animals treated with MPTP for the full 4 weeks. Animals treated with MPTP and 7,8-DHF also demonstrated increased levels of, a sprouting-associated protein, superior cervical ganglion-10 (SCG10), phosphorylated TrkB (pTrkB), and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) within the DL striatum and substantia nigra (SN) compared to the 4-week MPTP-treated animals. In addition, motor deficits seen in the 2- and 4-week MPTP-treated animals were restored following administration of 7,8-DHF. We are reporting here for the first time that intervention with 7,8-DHF blocks further loss of dopaminergic terminals and restores motor deficits in our progressive MPTP mouse model. Our data suggest that 7,8-DHF has the potential to be a translational therapy in PD.

Observation of edge instability limiting the pedestal growth in tokamak plasmas.

With fusion device performance hinging on the edge pedestal pressure, it is imperative to experimentally understand the physical mechanism dictating the pedestal characteristics and to validate and improve pedestal predictive models. This Letter reports direct evidence of density and magnetic fluctuations showing the stiff onset of an edge instability leading to the saturation of the pedestal on the Alcator C-Mod tokamak. Edge stability analyses indicate that the pedestal is unstable to both ballooning mode and kinetic ballooning mode in agreement with observations.

PKCα phosphorylation of RhoGDI2 at Ser31 disrupts interactions with Rac1 and decreases GDI activity.

Rho family GTPases control a diverse range of cellular processes, and their deregulation has been implicated in human cancer. Guanine nucleotide dissociation inhibitors (GDIs) bind and sequester GTPases in the cytosol, restricting their actions. RhoGDI2 is a member of the GDI family that acts as a metastasis suppressor in a variety of cancer types; however, very little is known about the regulation of this protein. Here, we present a mechanism for inactivation of RhoGDI2 via protein kinase C (PKC) phosphorylation of Ser31 in a region that contacts GTPases. In cells, RhoGDI2 becomes rapidly phosphorylated at Ser31 in response to phorbol 12-myristate 13-acetate stimulation. Based on the effects of pharmacological inhibitors and knockdown by siRNA, we determine that conventional type PKCα is responsible for this phosphorylation. Phospho-mimetic S31E-RhoGDI2 exhibits reduced binding to Rac1 relative to wild type, with a concomitant failure to reduce levels of activated endogenous Rac1 or remove Rac1 from membranes. These results reveal a mechanism of downregulation of RhoGDI2 activity through PKC-mediated phosphorylation of Ser31. We hypothesize that this mechanism may serve to neutralize RhoGDI2 function in tumors that express RhoGDI2 and active PKCα.

Blackawton bees.

BACKGROUND: Real science has the potential to not only amaze, but also transform the way one thinks of the world and oneself. This is because the process of science is little different from the deeply resonant, natural processes of play. Play enables humans (and other mammals) to discover (and create) relationships and patterns. When one adds rules to play, a game is created. THIS IS SCIENCE: the process of playing with rules that enables one to reveal previously unseen patterns of relationships that extend our collective understanding of nature and human nature. When thought of in this way, science education becomes a more enlightened and intuitive process of asking questions and devising games to address those questions. But, because the outcome of all game-playing is unpredictable, supporting this 'messyness', which is the engine of science, is critical to good science education (and indeed creative education generally). Indeed, we have learned that doing 'real' science in public spaces can stimulate tremendous interest in children and adults in understanding the processes by which we make sense of the world. The present study (on the vision of bumble-bees) goes even further, since it was not only performed outside my laboratory (in a Norman church in the southwest of England), but the 'games' were themselves devised in collaboration with 25 8- to 10-year-old children. They asked the questions, hypothesized the answers, designed the games (in other words, the experiments) to test these hypotheses and analysed the data. They also drew the figures (in coloured pencil) and wrote the paper. Their headteacher (Dave Strudwick) and I devised the educational programme (we call 'i,scientist'), and I trained the bees and transcribed the childrens' words into text (which was done with smaller groups of children at the school's local village pub). So what follows is a novel study (scientifically and conceptually) in 'kids speak' without references to past literature, which is a challenge. Although the historical context of any study is of course important, including references in this instance would be disingenuous for two reasons. First, given the way scientific data are naturally reported, the relevant information is simply inaccessible to the literate ability of 8- to 10-year-old children, and second, the true motivation for any scientific study (at least one of integrity) is one's own curiousity, which for the children was not inspired by the scientific literature, but their own observations of the world. This lack of historical, scientific context does not diminish the resulting data, scientific methodology or merit of the discovery for the scientific and 'non-scientific' audience. On the contrary, it reveals science in its truest (most naive) form, and in this way makes explicit the commonality between science, art and indeed all creative activities. PRINCIPAL FINDING: 'We discovered that bumble-bees can use a combination of colour and spatial relationships in deciding which colour of flower to forage from. We also discovered that science is cool and fun because you get to do stuff that no one has ever done before. (Children from Blackawton)'.

Motoneuron-specific NR3B gene: no association with ALS and evidence for a common null allele.

OBJECTIVE: The GRIN3B gene encodes NR3B, a motoneuron-specific member of the NMDA type of ionotropic glutamate receptors. NR3B reduces the Ca(2+)-permeability as well as the overall current of the receptor response and may thereby protect motoneurons against glutamate-mediated excitotoxicity. We tested whether genetic dysfunction of GRIN3B is implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). METHODS: We searched for mutations in the GRIN3B coding region (3.1 kb) in 117 individuals with familial ALS and in 46 individuals with sporadic ALS. We genotyped the newly identified GRIN3B null allele and four "tag single nucleotide polymorphisms (SNPs)" at the GRIN3B locus in 342 individuals with sporadic ALS and in 374 matched controls. The GRIN3B null allele frequency was determined in 2,128 individuals from a worldwide panel of 42 populations. We furthermore compared the GRIN3B coding sequence in primates (human-macaque) and rodents (rat-mouse) to evaluate the molecular evolution of GRIN3B. RESULTS: Thirty-two SNPs, including 16 previously unreported SNPs, one 27-bp deletion, a polymorphic CAG repeat, and a 4-bp insertion (insCGTT), were identified. Mutational and case-control studies did not reveal variants that cause or modify disease in ALS. Intriguing is an insCGTT variant that truncates the protein at its amino terminus and results in a GRIN3B null allele. We demonstrated a global distribution of the null allele with allele frequencies ranging between 0 and 0.38, and we delineated a null allele specific haplotype of 9.89 kb. Comparative genomic analysis across four taxa demonstrated accelerated evolution of NR3B in primates. CONCLUSIONS: Our study supports the conclusions that 1) GRIN3B does not seem to be associated with familial or sporadic ALS, 2) the GRIN3B null allele is a common polymorphism, 3) the GRIN3B null allele has arisen once and early in human evolution, and 4) the GRIN3B gene belongs to a group of nervous system-related genes that have been subjected to faster evolution during evolution.

Mutational analysis of the HIV-1 LTR as a promoter of negative sense transcription.

The HIV-1 gene promoter is a bi-directional promoter of transcription. We report the characterization of the negative sense promoter (NSP) by analysis of the effect on negative sense transcription of a series of LTR U3 region substitution mutants. Mutations in the region nt -58 to -183 (positive sense transcription initiation nt +1) reduced transcription to <15% of wild type NSP activity. This region, essential for NSP activity, was designated the core basal promoter. Over expression of NF-kappaB RelA(p65) and LEF-1 increased negative sense expression, as did over expression of H-ras oncogene, consistent with the presence of cognate sequence motifs for NF-kappaB, LEF-1 and RBF. We were also able to confirm that the NSP is a TATA-less promoter inhibited by HIV-1 Tat. Based on our findings, we propose a model for the interaction between the NSP and PSP, and the role of Tat in regulating the interaction.

Genetic susceptibility to renal injury in hypertension.

Substantial evidence indicates that hypertension plays a predominant role in the progression of most chronic renal diseases including diabetic nephropathy. Nevertheless, significant differences are observed in the susceptibility to develop hypertension-associated renal damage between individuals, racial groups and animal strains despite comparable hypertension. Recent studies employing a variety of genetic methods both in humans and in experimental models, have provided strong support for the potential importance of genetic factors and have suggested that genes influencing susceptibility to renal damage may be inherited separately from genes that influence blood pressure. However, due to the genetic complexity involved in a multifactorial trait such as the susceptibility to hypertensive renal damage, very limited progress has been achieved thus far in attempts to link such susceptibility to specific genetic mechanisms, chromosome regions and/or candidate genes. It is anticipated that the rapid recent advances in molecular genetic techniques and the simultaneous use of multiple complementary strategies, as is currently under way, will greatly facilitate this search and provide fundamental new insights into the pathogenesis of hypertensive renal damage.

Crystallization and rhenium MAD phasing of the acyl-homoserinelactone synthase EsaI.

Acyl-homoserine-L-lactones (AHLs) are diffusible chemical signals that are required for virulence of many Gram-negative bacteria. AHLs are produced by AHL synthases from two substrates, S-adenosyl-L-methionine and acyl-acyl carrier protein. The AHL synthase EsaI, which is homologous to the AHL synthases from other pathogenic bacterial species, has been crystallized in the primitive tetragonal space group P4(3), with unit-cell parameters a = b = 66.40, c = 47.33 A. The structure was solved by multiple-wavelength anomalous diffraction with a novel use of the rhenium anomalous signal. The rhenium-containing structure has been refined to a resolution of 2.5 A and the perrhenate ion binding sites and liganding residues have been identified.

c-Myb influences HIV type 1 gene expression and virus production.

c-Myb is expressed in proliferating T cells. Fifteen c-Myb-binding sites can be identified in the HIV-1 long terminal repeat (LTR), suggesting that c-Myb may regulate HIV-1 gene expression and virus replication. Increasing the cellular levels of c-Myb by transient transfection of CEM cells resulted in a 10- to 20-fold activation of HIV-1 LTR-driven gene expression and mutation of one high-affinity Myb-binding site within the LTR reduced this activation by 60 to 70%. Conversely, inhibition of c-Myb expression in MT-2 cells by treatment with c-myb antisense oligonucleotides decreased HIV-1 replication by 85%, as measured by reverse transcriptase activity and cytopathic effects. The effect of c-myb antisense oligonucleotides on HIV-1 gene expression and virus particle production appeared to be independent of cell proliferation, but dependent on the presence of c-Myb activity mediated through the HIV-1 LTR. These data show that c-myb expression affects HIV-1 replication in CD4(+) T cells.

Remarkable spectator ligand effect on the rate constant of ligand substitution of (aqua)ruthenium(II) complexes.

The influence of two different di(1-pyrazolyl)alkane ligands on the rate constant of aqua ligand substitution of ruthenium(II) complexes with the formula [Ru(H2O)(L2)(tpmm)]2+ (L2 = di(1-pyrazolyl)methane (DPMet) or 2,2-di(1-pyrazolyl)propane (DPPro)) was investigated. A 9.4 x 10(5)-fold increase in the rate constant of ligand substitution at pH = 6.86 was observed when DPMet was replaced with DPPro. This remarkable increase was unexpected, considering that these bidentate ligands appear quite similar. To help lend insight into this dramatic spectator ligand effect, the activation parameters for the ligand substitution reactions were determined, and single-crystal X-ray data were collected on the structurally analogous (chloro)ruthenium(II) complexes, [Ru(Cl)(L2)(tpmm)]+. These results are discussed in the context of a heteroscorpionate effect exerted by the DPPro ligand.

Linkage and redox isomerism in ruthenium complexes of catecholate, semi-quinone, and o-acylphenolate ligands derived from tri- and tetrahydroxy-9,10-anthracenediones.

The complexes Ru(CO)(2)L(2)(PHAQ-2H) (PHAQ = 1,2,4-trihydroxy-9,10-anthracenedione (PUR), 1,2,3- trihydroxy-9,10-anthracenedione (AG), and 1,2,5,8-tetrahydroxy-9,10-anthracenedione (QAL); L = PPh(3), PCy(3), PBu(3)), and Ru(CO)(dppe)(PBu(3))(PHAQ-2H), containing catecholate-type ligands were prepared. The complex Ru(CO)(2)(PBu(3))(2)(AG-2H) crystallizes in the space group P2(1)/n (No. 14 var) with a = 13.317(2), b = 15.628(2), c = 21.076(3) A, beta = 101.660(10) degrees, Z = 4; the crystal structure shows it to contain a 2,3-catecholate ligand. The electrochemistry of these complexes was examined, and the semi-quinone complexes [Ru(CO)(2)L(2)(PHAQ-2H)](1+) and [Ru(CO)(dppe)(PBu(3))(PHAQ-2H)](1+) were generated by chemical oxidation. One example of an o-acylphenolate complex, HRu(CO)(PCy(3))(2)(PUR-H), is also reported.

Kidney-specific chromosome transfer in genetic hypertension: the Dahl hypothesis revisited.

BACKGROUND: A central dogma in the field of essential hypertension research is that the genetic transmission of increased blood pressure is determined solely by the genotype of the kidney. This concept is based in large part on studies in experimental rat models of spontaneous hypertension in which transplantation of a kidney from a hypertensive strain into a normotensive strain was reported to increase blood pressure, and transplantation of a kidney from a normotensive strain into a hypertensive strain was reported to decrease blood pressure. The enduring interpretation of these now classic experiments remains virtually unchanged from the view originally espoused a quarter century ago by Lewis Dahl, one of the founding fathers of the field of genetic hypertension research: "Blood pressure is determined by the genotype of the donor kidney and not the genotype of the recipient." METHODS: To test the Dahl hypothesis, we determined the blood pressure effects of selective intrarenal versus extrarenal exchange of single chromosome regions between the spontaneously hypertensive rat (SHR) and the normotensive Brown Norway (BN) rat. RESULTS: The replacement of a defined segment of chromosome 1 in the SHR with the corresponding chromosome region of the BN rat was sufficient to attenuate hypertension when selectively achieved either inside the kidney or outside the kidney. CONCLUSIONS: The current finding (1) demonstrates that naturally occurring genetic variants exist that can regulate blood pressure when selectively expressed outside the kidney as well as inside the kidney, and (2) compels reconsideration of the long-held view that in essential hypertension, the genetic transmission of increased blood pressure is determined solely by the genotype of the kidney.