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PubMed1997

The neuronal isoform of constitutive nitric oxide synthase is up-regulated in the macula densa of angiotensinogen gene-knockout mice.

Angiotensinogen gene-knockout (Atg -/-) mice lacking angiotensin II exhibit chronic hypotension and an increase in renal renin gene expression. The present study was designed to provide evidence for the possible involvement of neuronal type nitric oxide synthase (N-NOS) at the macula densa in the increased renin production in Atg -/- mice. The enzyme activity of N-NOS was histochemically detected by NADPH diaphorase (NADPHd) reaction combined with N-NOS immunohistochemistry. N-NOS mRNA expression in the renal cortical tissue was determined using reverse transcription-PCR in a semiquantitative manner. The levels of renal renin mRNA were evaluated by Northern blot analysis. In the kidneys of wild-type (Atg +/+) mice, N-NOS activity was localized to the macula densa as reported previously. On the other hand, N-NOS-positive macula densa cells of Atg -/- mice were distributed beyond the original location of the macula densa. They often occupy the entire cross-sectional profiles of the tubules. In addition, Atg -/- mice showed a stronger signal intensity for the enzyme reaction than Atg +/+ mice. The mean total number of N-NOS-positive cells per 100 glomeruli was 6 times higher in Atg -/- mice than in Atg +/+ mice. Semiquantitative reverse transcription-PCR revealed an increase in the N-NOS mRNA level in renal cortical tissue of Atg -/- mice compared with Atg +/+ mice. Furthermore, the selective inhibition of N-NOS activity by 7-nitrondazole significantly decreased the level of renal renin mRNA in Atg -/- mice. These results suggest that increased N-NOS activity at the macula densa is involved a renal renin overproduction in Atg -/- mice.

Angiotensinogen↗
PubMed1998

Endocrinological abnormalities in angiotensinogen-gene knockout mice: studies of hormonal responses to dietary salt loading.

OBJECTIVE: Physiological roles of the renin-angiotensin system in maintaining blood pressure and sodium-water balance in angiotensinogen gene-knockout mice were evaluated with special reference to endogenous pressor substances. METHODS: Angiotensinogen-gene knockout mice and control mice were fed a 0.3 or 4% NaCl diet for 2 weeks. Systolic blood pressure and urinary excretions of electrolytes, creatinine, aldosterone, adrenaline, noradrenaline, dopamine and vasopressin were measured. RESULTS: About 60% of our angiotensinogen-gene knockout mice did not survive until weaning. These mice presented with hypotension and polyuria. Urinary excretion of aldosterone from such mice was significantly lower (not detected) than that from control mice (2.0+/-0.3 pg/mg creatinine). In contrast, urinary excretion of vasopressin from angiotensinogen-gene knockout mice (0.7+/-0.1 ng/mg creatinine) was greater than that from control mice (0.3+/-0.1 ng/mg creatinine), and those of adrenaline and of noradrenaline were similar for knockout and control mice. After salt loading (a 4% NaCl diet), angiotensinogen-gene knockout mice exhibited a significant increase in systolic blood pressure (from 68.3+/-2.9 to 95.9+/-5.9 mmHg), significant decreases in urinary excretions of adrenaline (from 65+/-8 to 40+/-7 pg/mg creatinine) and noradrenaline (from 467+/-48 to 281+/-41 pg/mg creatinine) and no change in excretion of vasopressin compared with such mice fed a 0.3% NaCl diet CONCLUSION: The present results with angiotensinogen-gene knockout mice confirm that the renin-angiotensin system plays fundamental roles in maintaining the blood pressure and sodium-water balance. Because the vasopressin and catecholaminergic systems may be altered by lack of angiotensin in angiotensinogen-gene knockout mice, these systems perhaps are not able to restore blood pressure and sodium-water depletion to normal levels in these mice.

Aldosterone↗
PubMed2001

Nitric oxide synthase gene knockout mice do not become hypertensive during pregnancy.

OBJECTIVE: The purpose of this study was to test whether omitting the vasodilator nitric oxide that is derived from any 1 of the 3 isoforms of nitric oxide synthase results in hypertension during pregnancy. STUDY DESIGN: We measured systolic blood pressure before, during, and after pregnancy using an automated tail cuff method in 3 mutant (gene knockout) mouse strains in which the gene for neuronal nitric oxide, inducible nitric oxide, or endothelial nitric oxide was disrupted by gene targeting. RESULTS: In neuronal nitric oxide gene knockout mice (n = 10), blood pressure was 100 +/- 3 mm Hg, not significantly different from 101 +/- 3 mm Hg in matched wild-type control mice (n = 10). Pregnancy did not change blood pressure or heart rate in either group. In inducible nitric oxide gene knockout mice (n = 9), blood pressure was 110 +/- 3 mm Hg, the same as in the wild-type control mice (110 +/- 2 mm Hg; n = 14). Blood pressure was unaffected by pregnancy in either group of mice. However, heart rate was significantly less in knockout mice (647 +/- 11 beats/min vs 666 +/- 9 beats/min; P <.005); this difference persisted through pregnancy. In endothelial nitric oxide gene knockout mice (n = 8), blood pressure was higher before pregnancy (114 +/- 4 mm Hg vs 103 +/- 4 mm Hg; P <.05) than in wild-type control mice (n = 9), but this difference disappeared during pregnancy, returning only after delivery. Heart rates were not different before pregnancy and were unaffected by pregnancy. CONCLUSION: There was no apparent increase in systolic blood pressure in any of the 3 nitric oxide synthase gene knockout strains during pregnancy compared to the wild-type control mice. This suggests that, at least in the mouse, genetic deficiency of any 1 isoform of nitric oxide synthase does not result in pregnancy-induced hypertension.

Animals↗
PubMed2006

Pol II-expressed shRNA knocks down Sod2 gene expression and causes phenotypes of the gene knockout in mice.

RNA interference (RNAi) has been used increasingly for reverse genetics in invertebrates and mammalian cells, and has the potential to become an alternative to gene knockout technology in mammals. Thus far, only RNA polymerase III (Pol III)-expressed short hairpin RNA (shRNA) has been used to make shRNA-expressing transgenic mice. However, widespread knockdown and induction of phenotypes of gene knockout in postnatal mice have not been demonstrated. Previous studies have shown that Pol II synthesizes micro RNAs (miRNAs)-the endogenous shRNAs that carry out gene silencing function. To achieve efficient gene knockdown in mammals and to generate phenotypes of gene knockout, we designed a construct in which a Pol II (ubiquitin C) promoter drove the expression of an shRNA with a structure that mimics human miRNA miR-30a. Two transgenic lines showed widespread and sustained shRNA expression, and efficient knockdown of the target gene Sod2. These mice were viable but with phenotypes of SOD2 deficiency. Bigenic heterozygous mice generated by crossing these two lines showed nearly undetectable target gene expression and phenotypes consistent with the target gene knockout, including slow growth, fatty liver, dilated cardiomyopathy, and premature death. This approach opens the door of RNAi to a wide array of well-established Pol II transgenic strategies and offers a technically simpler, cheaper, and quicker alternative to gene knockout by homologous recombination for reverse genetics in mice and other mammalian species.

3' Untranslated Regions↗
PubMed2003

[Study on gene knockout using red system in Shigella flexneri].

The technology of gene knockout using lambda Red system in bacteria has been developed lately, but its application being limited to Esherichia coli. In order to get some experiences in other bacteria we select four genes, including alkA, wcaJ, yphF and dam, to test gene knockout using Red system in E. coli and Shigella. As a result, three genes were successfully knocked out in E. coli except dam while only alkA gene was knocked out in Shigella. It showed that the Red system should be improved if it was to be effectively used in Shigella and other bacteria.

Bacterial Proteins↗
PubMed2000

Experimental cancer cachexia: the role of host-derived cytokines interleukin (IL)-6, IL-12, interferon-gamma, and tumor necrosis factor alpha evaluated in gene knockout, tumor-bearing mice on C57 Bl background and eicosanoid-dependent cachexia.

MCG 101 tumors were implanted sc. on wild-type C57 Bl and gene knockout mice to evaluate the role of host-produced cytokines [interleukin (IL)-6, IL-12, IFNgamma, tumor necrosis factor (TNF) receptor 1, and TNF receptor 2] to explain local tumor growth, anorexia, and carcass weight loss in a well-defined model with experimental cachexia. Indomethacin was provided in the drinking water to explore interactions between host and tumor-derived prostaglandins and proinflammatory cytokines for tumor growth. Wild-type tumor-bearing mice developed cachexia because of rapid tumor growth, which were both attenuated in IL-6 gene knockouts. Similar findings were observed after provision of anti-IL-6 to wild-type tumor-bearing mice. Alterations in food intake were not directly related to systemic IL-6 but rather secondarily to IL-6-dependent tumor growth. The absence of host-derived IL-12, IFN-gamma, or the TNF receptor 1 or receptor 2 gene did not attenuate tumor growth or improve subsequent cachexia. Thus, carcass weight loss was not improved by the omission of host cytokine (TNF-alpha, IL-12, or IFN-gamma) except for IL-6. Systemic indomethacin provision decreased plasma prostaglandin E2 in five of six groups of gene knockout tumor-bearing mice, which was associated with improved carcass weight in these groups. Indomethacin seemed to improve food intake to a similar extent in both wild-type and gene knockouts, which agree with the speculation that eicosanoids are more important to explain anorexia than host cytokines. Our results demonstrate that host- and tumor-derived cytokines and prostaglandins interact with tumor growth and promote cachexia in a more complex fashion than usually presented based on previous information in studies on either anti-cytokine experiments in vivo or on gene knockouts with respect to a "single cytokine model." Overall, host cytokines were quantitatively less important than tumor-derived cytokines to explain net tumor growth, which indirectly explains subsequent cachexia and anorexia.

Animals↗
PubMed2025

CRISPR-based gene knockout in the model haloarchaeon Haloferax mediterranei.

Halophilic archaea, a specialized group of extremophiles that inhabit hypersaline environments, exhibit distinctive physiological and metabolic features. Traditional genetic manipulation of these organisms, predominantly reliant on homologous recombination techniques, suffers from limitations such as complex procedures and extended timelines, which hinder functional genomics research and the development of practical applications. This study established a CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-mediated gene knockout system in the model halophilic archaeon Haloferax mediterranei. A polyethylene glycol (PEG)-mediated transformation method was used to deliver a plasmid carrying a mini-CRISPR array into H. mediterranei. The crtB gene, involved in pigment synthesis, was successfully knocked out, demonstrating the feasibility of CRISPR-based editing in H. mediterranei. To further validate the reliability and targeting accuracy of the system, the hlyR4 gene, encoding an extracellular serine protease, was also disrupted. The CRISPR-mediated gene knockout efficiency for hlyR4 reached 27%, significantly higher than the approximately 3% efficiency achieved with conventional homologous recombination. The establishment of this CRISPR-based gene knockout system provides a more efficient genetic tool for H. mediterranei and lays a new experimental foundation for exploiting microbial resources from extreme environments. In this study, H. mediterranei was selected as the model organism for haloarchaea. For the first time, we successfully constructed a CRISPR-based gene knockout system in a model halophilic archaeon. This system provides a solution for CRISPR-based gene knockout tools, which are currently unavailable in model halophilic archaea, and offers an effective tool for functional genomics studies in extremophiles.

Haloferax mediterranei↗
PubMed2006

[Exogenous estrogen improved calcium homeostasis and skeletal mineralization in vitamin D receptor gene knockout female mice].

It is well known that estrogen can inhibit bone absorption, decrease bone turnover and preserve bone mass. Some studies indicated that the effect of estrogen on calcium and bone is relative to vitamin D system, while others also reported that this effect of estrogen is independent of vitamin D. The genomic effect of 1alpha, 25(OH)(2)D(3)is mediated by the nuclear vitamin D receptor (VDR) in a ligand-dependent manner. Hypocalcemia, hyperparathyroidism and osteomalacia are developed in VDR gene knockout mice. To determine whether the effect of estrogen on calcium and bone is dependent on VDR, this study examined the effect of exogenous estrogen on calcium and bone homeostasis in VDR gene knockout mice. Male and female wild type (WT) and VDR gene knockout heterozygous mice were mated each other and the genotyping of their offsprings were determined by PCR. At age of 21-day, WT and knockout mice were weaned and treated by one of three different regimens: (1) WT-vehicle group: the WT mice were injected with normal saline; (2) VDR KO-vehicle group: the VDR gene knockout mice were injected with normal saline; (3) VDR KO-E group: the VDR gene knockout mice were subcutaneously injected with estradiol, 0.2 mug per mouse, once daily for 1 month. The bone mineral density (BMD) of mice was measured using dual-energy X-ray absorptiometry. All mice were sacrificed at age of 50-day. Blood was taken by heart puncture under anesthesia and serum calcium was measured by autoanalyser.Tibiae were removed, fixed and embedded with the methylmethacrylate (MMA), and undecalcified sections were cut. These sections were stained for mineral with the von Kossa staining procedure and counterstained with toluidine blue. Static histomorphometric analyses were performed on those stained sections. The results showed that the serum calcium level was (2.10+/-0.37) mmol/L in the VDR KO-vehicle mice and rose to (2.80+/-0.41) mmol/L in the VDR KO-E mice although it was still lower than WT-vehicle mice [(3.10+/-0.48) mmol/L]. BMD and mineralized trabeculer volume were increased significantly in VDR KO-E group compared with that in VDR KO-vehicle group. These results suggest that exogenous estrogen can improve calcium absorption and skeletal mineralization in a VDR-independent manner.

Animals↗
PubMed2002

Increased glycosphingolipid levels in serum and aortae of apolipoprotein E gene knockout mice.

The apolipoprotein E gene knockout (apoE-/-) mouse develops atherosclerosis that shares many features of human atherosclerosis. Increased levels of glycosphingolipid (GSL) have been reported in human atherosclerotic lesions; however, GSL levels have not been studied in the apoE-/- mouse. Here we used HPLC methods to analyze serum and aortic GSL levels in apoE-/- and C57BL/6J control mice. The concentrations of glucosyl ceramide (GlcCer), lactosyl ceramide (LacCer), GalNAcbeta1-4Galbeta1-4Glc-Cer (GA2), and ceramide trihexoside (CTH) were increased by approximately 7-fold in the apoE-/- mouse serum compared with controls. The major serum ganglioside, N-glycolyl GalNAcbeta1-4[NeuNAcalpha2-3]Galbeta1-4Glc-Cer (N-glycolyl GM2), was increased in concentration by approximately 3-fold. A redistribution of GSLs from HDL to VLDL populations was also observed in the apoE-/- mice. These changes were accompanied by an increase in the levels of GSLs in the aortic sinus and arch of the apoE-/- mice. The spectrum of gangliosides present in the aortic tissues was more complex than that found in the lipoproteins, with the latter represented almost entirely by N-glycolyl GM2 and the former comprised of NeuNAcalpha2-3Galbeta1-4Glc-Cer (GM3), GM2, N-glycolyl GM2, GM1, GD3, and GD1a. In conclusion, neutral GSL and ganglioside levels were increased in the serum and aortae of apoE-/- mice compared with controls, and this was associated with a preferential redistribution of GSL to the proatherogenic lipoprotein populations. The apoE-/- mouse therefore represents a useful model to study the potential role of GSL metabolism in atherogenesis.

Animals↗
PubMed1998

Lessons from gene knockouts.

The authors describe the technique for the application of homologous recombination in embryonic stem cells, which is now widely used to engineer mice which carry specific knockouts of genes. A summary is given of some of the knowledge of the pathogenesis of and resistance to infections with parasites, bacteria, or viruses which has accumulated during recent years, based on the investigation of knockout mice. Special emphasis is placed on knockout animals which lack components of the cytokine network, lack genes which are critical for the correct presentation of antigens or are deficient in different immune cell subsets. In addition, a brief explanation is offered of the possibilities for inducing targeted deletions or mutations in genes of livestock species (e.g., by nuclear transfer or by mutagenesis using the alkylating agent N-ethyl-N-nitrosourea) which could lead to the breeding of animals which are resistant to infectious diseases in the future.

Animals↗
PubMed1996

Subregion- and cell type-restricted gene knockout in mouse brain.

Using the phage P1-derived Cre/loxP recombination system, we have developed a method to create mice in which the deletion (knockout) of virtually any gene of interest is restricted to a subregion or a specific cell type in the brain such as the pyramidal cells of the hippocampal CA1 region. The Cre/loxP recombination-based gene deletion appears to require a certain level of Cre protein expression. The brain subregional restricted gene knockout should allow a more precise analysis of the impact of a gene mutation on animal behaviors.

Animals↗
PubMed1997

Analysis of two pharmacologically predicted endothelin B receptor subtypes by using the endothelin B receptor gene knockout mouse.

1. This study was performed to clarify whether the endothelin (ET) receptor subtypes mediating two pharmacologically heterogeneous response to ETH receptor agonists in normal mice are the product(s) of a single ETB receptor gene. 2. Vasodilator responses to sarafotoxin S6c (S6c) in the thoracic aorta and contractile responses to ET-1 and IRL1620 in the stomach were examined in tissues from normal and ETB receptor gene knockout mice, in the absence and presence of an ETA receptor antagonist, BQ-123, or an ETA/ETB receptor antagonist, PD142893. 3. In the normal mouse aorta precontracted with phenylephrine, S6c (0.1-100 nM) caused concentration-dependent relaxations (pD2 = 8.4). BQ-123 had no effect on these responses. However, PD142893 almost abolished the relaxations induced by 0.1-300 nM S6c. 4. In aortae taken from ETB receptor gene knockout mice, S6c up to 1 microM failed to cause relaxations, confirming that ETB receptors are involved in mediating this response. 5. In normal mouse gastric fundus, 0.1 nM-1 microM ET-1, S6c or IRL1620 caused dose-dependent, BQ-123-insensitive contractions, which were much more resistant to PD142893 than S6c-induced relaxations of the aorta. The pD2 values for S6c in the absence and presence of PD142893 (10 microM) were 8.12 +/- 0.11 and 7.70 +/- 0.11, respectively. 6. In the gastric fundus of the ETB receptor gene knockout mouse, S6c and IRL1620 caused no contractions. ET-1 (0.1 nM-1 microM) caused contractions sensitive to both BQ-123 and PD142893, indicating that only ETA receptors mediate ET-1-induced contractions of the knockout mouse gastric fundus. 7. Since both the PD142893-sensitive vasodilator response of the aorta and the PD142893-resistant contractile response of the gastric fundus to S6c were completely absent in the ETB receptor gene knockout mouse, we conclude that the two pharmacologically heterogeneous responses to S6c are mediated by receptors derived from the same ETB receptor gene.

Animals↗
PubMed2004

An efficient method for producing alpha(1,3)-galactosyltransferase gene knockout pigs.

We have reported relatively efficient methods for somatic cell nuclear transfer and for knocking out the alpha(1,3)-galactosyltransferase (alpha1,3-GT) gene in porcine fetal fibroblasts using a nonisogenic promoterless construct approach. Here we report the production of alpha1,3-GT gene knockout pigs using these procedures. Seven alpha1,3-GT gene knockout cell clones were identified by long-range PCR from 108 neomycin resistant (neo(R)) colonies, giving a 6.5% targeting efficiency. Three cell clones were used for nuclear transfer. Nuclear transfer was performed using a fusion before activation protocol using in vitro-matured adult oocytes. Between 51 and 110 fused couplets were transferred to 10 recipients synchronized 1 day behind the embryos. Parturition was induced on day 115, and piglets were delivered by caesarean section. Four recipients gave birth to a total of 18 live piglets. All pigs were female, and all three clones resulted in the birth of live pigs. alpha1,3-GT gene knockout pigs were identified by long-range PCR and confirmed by Southern blot analysis. The efficiency (embryos transferred/piglets born) of our cloning protocol was 1.9% for all transfers and 4.6% for animals that gave birth.

Animals↗
PubMed2004

Arsenic resistance in Halobacterium sp. strain NRC-1 examined by using an improved gene knockout system.

The genome sequence of Halobacterium sp. strain NRC-1 encodes genes homologous to those responsible for conferring resistance to arsenic. These genes occur on both the large extrachromosomal replicon pNRC100 (arsADRC and arsR2M) and on the chromosome (arsB). We studied the role of these ars genes in arsenic resistance genetically by construction of gene knockouts. Deletion of the arsADRC gene cluster in a Halobacterium NRC-1 Deltaura3 strain resulted in increased sensitivity to arsenite and antimonite but not arsenate. In contrast, knockout of the chromosomal arsB gene did not show significantly increased sensitivity to arsenite or arsenate. We also found that knockout of the arsM gene produced sensitivity to arsenite, suggesting a second novel mechanism of arsenic resistance involving a putative arsenite(III)-methyltransferase. These results indicate that Halobacterium sp. strain NRC-1 contains an arsenite and antimonite extrusion system with significant differences from bacterial counterparts. Deletion analysis was facilitated by an improved method for gene knockouts/replacements in Halobacterium that relies on both selection and counterselection of ura3 using a uracil dropout medium and 5-fluoroorotic acid. The arsenite and antimonite resistance elements were shown to be regulated, with resistance to arsenic in the wild type inducible by exposure to a sublethal concentration of the metal. Northern hybridization and reverse transcription-PCR analyses showed that arsA, arsD, arsR, arsM, arsC, and arsB, but not arsR2, are inducible by arsenite and antimonite. We discuss novel aspects of arsenic resistance in this halophilic archaeon and technical improvements in our capability for gene knockouts in the genome.

Antimony↗
PubMed2002

Hepatocellular carcinoma caused by loss of heterozygosity in Lkb1 gene knockout mice.

Germline mutations of the LKB1 gene are associated with Peutz-Jeghers syndrome, which is characterized by mucocutaneous pigmentation and gastrointestinal hamartoma with an increased risk of cancer development. To investigate the role of LKB1 in vivo, we have recently constructed Lkb1 gene knockout mice. Because of Lkb1 gene haploinsufficiency, the heterozygous Lkb1 mice develop gastrointestinal polyps of which the histological characteristics resemble those of the Peutz-Jeghers syndrome hamartomas. Here we demonstrate that the Lkb1 (+/-) mice develop hepatocellular carcinomas (HCCs). In Lkb1 (+/-) mice >50 weeks of age, >70% of the male mice developed HCCs, whereas only 20% of the females had HCCs, showing a sex difference in the susceptibility. Histological examinations revealed various types of HCCs, such as "trabecular," "clear cell," "pseudoglandular," and "sarcomatous" types, which were strikingly similar to those found in human HCCs. Western blotting and PCR analyses showed loss of Lkb1 heterozygosity in all of the HCC tissues examined, indicating a tumor suppressor role of LKB1 in the mouse liver. These results suggest that lack of LKB1 is a novel mechanism for HCC development. Thus, the Lkb1 (+/-) knockout mutant should be an important and useful model for human HCC.

AMP-Activated Protein Kinases↗
PubMed2004

[Screen selection of target genes regulated by HSF1 in heat shock response from myocardium of gene knockout mice].

OBJECTIVE: To screen select target genes regulated by heat shock transcription factor 1 (HSF1 ) in heat shock response from myocardium of HSF1 gene knockout mice using cDNA chip. METHODS: HSF1 knockout mice were subjected to heat shock treatment (42 degrees C for 15 minutes, and recovered for 3 hours), and cDNA chip containing 15 000 mouse cDNAs were employed to investigate the expression of genes regulated by HSF1 in the myocardium. Then 4 of the differentially expressed genes in the myocardium of HSF1 knockout mice were further confirmed by RT-PCR. The promoter regions of the differentially expressed genes were analysed by TESS software to find HSE. RESULTS: Three hundred and ninety-eight genes were down - regulated in the myocardium of HSF1 knockout mice in heat shock response,with 173 known. Whereas 641 genes were up-regulated in the myocardium, with 235 known. The 5 down-regulated genes and 6 up-regulated ones were shown to contain HSE in their promoter regions. CONCLUSION: In heat shock response, expression of multiple genes is regulated directly or indirectly by HSF1.

Animals↗
PubMed1997

Gene knockout of the intracellular amylase gene by homologous recombination in Streptococcus bovis.

Streptococcus bovis expresses two different amylases, one intracellular and the other secreted. A suicide vector containing part of the intracellular alpha-amylase gene from Streptococcus bovis WI-1 was recombined into the S. bovis WI-1 chromosome to disrupt the endogenous gene. Recombination was demonstrated by Southern blot, and zymogram analysis confirmed the loss of the intracellular amylase. Amylase activity in cell-free extracts of the recombinant grown in the presence of 1% starch was only 7% of wild type. The rate of logarithmic growth of the recombinant was 15-20% of the wild type in medium containing either 1% glucose, starch, or cellobiose. Revertants and non-amylase control recombinants had logarithmic growth rates that were the same as wild type. Plasmid transformants containing multiple copies of the cloned gene expressed up to threefold higher levels of intracellular amylase activity than wild type but did not demonstrate elevated growth rates. These results suggest that a critical level of expression of the intracellular amylase gene may be important for rapid growth of the bacterium.

Amylases↗
PubMed2025

CRISPR/Cas9-Mediated Gene-Knockout and In Situ Complementation System for Phytophthora sojae.

The establishment of reliable and efficient systems for genome editing in Phytophthora is very important for studying gene functions. Here, step-by-step methods for CRISPR/Cas9-based gene knockout and in situ complementation for Phytophthora sojae are presented. These steps include the sgRNA design, Cas9-sgRNA plasmid construction, homologous replacement, complementation vector construction, P. sojae transformation, and detection of mutations for both gene knockout and in situ complementation. These methods may also potentially be adapted for other Phytophthora species.

Phytophthora↗