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Chandra R, Aryal DK, Douros JD, Shahid R, Davis SJ, Campbell JE, Ilkayeya O, White PJ, Rodriguez R, Newgard CB, Wetsel WC, Liddle RA. Ildr1 gene deletion protects against diet-induced obesity and hyperglycemia. PLoS One 2022; 17:e0270329. [PMID: 35749484 PMCID: PMC9231709 DOI: 10.1371/journal.pone.0270329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/09/2022] [Indexed: 11/24/2022] Open
Abstract
Objective Immunoglobulin-like Domain-Containing Receptor 1 (ILDR1) is expressed on nutrient sensing cholecystokinin-positive enteroendocrine cells of the gastrointestinal tract and it has the unique ability to induce fat-mediated CCK secretion. However, the role of ILDR1 in CCK-mediated regulation of satiety is unknown. In this study, we examined the effects of ILDR1 on food intake and metabolic activity using mice with genetically-deleted Ildr1. Methods The expression of ILDR1 in murine tissues and the measurement of adipocyte cell size were evaluated by light and fluorescence confocal microscopy. The effects of Ildr1 deletion on mouse metabolism were quantitated using CLAMS chambers and by targeted metabolomics assays of multiple tissues. Hormone levels were measured by ELISA. The effects of Ildr1 gene deletion on glucose and insulin levels were determined using in vivo oral glucose tolerance, meal tolerance, and insulin tolerance tests, as well as ex vivo islet perifusion. Results ILDR1 is expressed in a wide range of tissues. Analysis of metabolic data revealed that although Ildr1-/- mice consumed more food than wild-type littermates, they gained less weight on a high fat diet and exhibited increased metabolic activity. Adipocytes in Ildr1-/- mice were significantly smaller than in wild-type mice fed either low or high fat diets. ILDR1 was expressed in both alpha and beta cells of pancreatic islets. Based on oral glucose and mixed meal tolerance tests, Ildr1-/- mice were more effective at lowering post-prandial glucose levels, had improved insulin sensitivity, and glucose-regulated insulin secretion was enhanced in mice lacking ILDR1. Conclusion Ildr1 loss significantly modified metabolic activity in these mutant mice. While Ildr1 gene deletion increased high fat food intake, it reduced weight gain and improved glucose tolerance. These findings indicate that ILDR1 modulates metabolic responses to feeding in mice.
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Affiliation(s)
- Rashmi Chandra
- Department of Medicine, Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail: (RC); (RAL)
| | - Dipendra K. Aryal
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Jonathan D. Douros
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Rafiq Shahid
- Department of Medicine, Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Supriya J. Davis
- Department of Medicine, Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina, United States of America
- Swarthmore College, Swarthmore, Pennsylvania, United States of America
| | - Jonathan E. Campbell
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
| | - Olga Ilkayeya
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, North Carolina, United States of America
| | - Phillip J. White
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, North Carolina, United States of America
| | - Ramona Rodriguez
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, United States of America
- Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University, Durham, North Carolina, United States of America
| | - Christopher B. Newgard
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, United States of America
- Sarah W. Stedman Nutrition and Metabolism Center, Duke University, Durham, North Carolina, United States of America
| | - William C. Wetsel
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, United States of America
- Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University, Durham, North Carolina, United States of America
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Rodger A. Liddle
- Department of Medicine, Division of Gastroenterology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Veterans Affairs Medical Center, Durham, North Carolina, United States of America
- * E-mail: (RC); (RAL)
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Analysis of Gene Expression Using lacZ Reporter Mouse Lines. Methods Mol Biol 2021. [PMID: 33606204 DOI: 10.1007/978-1-0716-1008-4_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Reporter mice transgenically expressing the bacterial (E. coli) lacZ gene encoding β-galactosidase (β-gal, EC 3.2.1.23) are a versatile and extensively used tool to study gene expression and cell lineage patterns. Enzymatic activity of the β-gal reporter can be effectively visualized at cellular resolution either histochemically using 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-gal) or by immunofluorescent detection using a β-gal-specific antibody. Here, we summarize protocols for the localization of β-gal expressing cells in whole embryos or organs as well as in histological tissue sections of lacZ reporter mice and discuss their limitations and common pitfalls.
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Materna SC, Sinha T, Barnes RM, Lammerts van Bueren K, Black BL. Cardiovascular development and survival require Mef2c function in the myocardial but not the endothelial lineage. Dev Biol 2018; 445:170-177. [PMID: 30521808 DOI: 10.1016/j.ydbio.2018.12.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 11/28/2018] [Accepted: 12/03/2018] [Indexed: 01/27/2023]
Abstract
MEF2C is a member of the highly conserved MEF2 family of transcription factors and is a key regulator of cardiovascular development. In mice, Mef2c is expressed in the developing heart and vasculature, including the endothelium. Loss of Mef2c function in germline knockout mice leads to early embryonic demise and profound developmental abnormalities in the cardiovascular system. Previous attempts to uncover the cause of embryonic lethality by specifically disrupting Mef2c function in the heart or vasculature failed to recapitulate the global Mef2c knockout phenotype and instead resulted in relatively minor defects that did not compromise viability or result in significant cardiovascular defects. However, previous studies examined the requirement of Mef2c in the myocardial and endothelial lineages using Cre lines that begin to be expressed after the expression of Mef2c has already commenced. Here, we tested the requirement of Mef2c in the myocardial and endothelial lineages using conditional knockout approaches in mice with Cre lines that deleted Mef2c prior to onset of its expression in embryonic development. We found that deletion of Mef2c in the early myocardial lineage using Nkx2-5Cre resulted in cardiac and vascular abnormalities that were indistinguishable from the defects in the global Mef2c knockout. In contrast, early deletion of Mef2c in the vascular endothelium using an Etv2::Cre line active prior to the onset of Mef2c expression resulted in viable offspring that were indistinguishable from wild type controls with no overt defects in vascular development, despite nearly complete early deletion of Mef2c in the vascular endothelium. Thus, these studies support the idea that the requirement of MEF2C for vascular development is secondary to its requirement in the heart and suggest that the observed failure in vascular remodeling in Mef2c knockout mice results from defective heart function.
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Affiliation(s)
- Stefan C Materna
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Molecular Cell Biology, School of Natural Sciences, University of California, Merced, Merced, CA 95343, USA
| | - Tanvi Sinha
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ralston M Barnes
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Kelly Lammerts van Bueren
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Brian L Black
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA.
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Jensen TØ, Pogrebnyakov I, Falkenberg KB, Redl S, Nielsen AT. Application of the thermostable β-galactosidase, BgaB, from Geobacillus stearothermophilus as a versatile reporter under anaerobic and aerobic conditions. AMB Express 2017; 7:169. [PMID: 28875485 PMCID: PMC5585113 DOI: 10.1186/s13568-017-0469-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 08/29/2017] [Indexed: 11/10/2022] Open
Abstract
Use of thermophilic organisms has a range of advantages, but the significant lack of engineering tools limits their applications. Here we show that β-galactosidase from Geobacillus stearothermophilus (BgaB) can be applicable in a range of conditions, including different temperatures and oxygen concentrations. This protein functions both as a marker, promoting colony color development in the presence of a lactose analogue S-gal, and as a reporter enabling quantitative measurement by a simple colorimetric assay. Optimal performance was observed at 70 °C and pH 6.4. The gene was introduced into G. thermoglucosidans. The combination of BgaB expressed from promoters of varying strength with S-gal produced distinct black colonies in aerobic and anaerobic conditions at temperatures ranging from 37 to 60 °C. It showed an important advantage over the conventional β-galactosidase (LacZ) and substrate X-gal, which were inactive at high temperature and under anaerobic conditions. To demonstrate the versatility of the reporter, a promoter library was constructed by randomizing sequences around −35 and −10 regions in a wild type groES promoter from Geobacillus sp. GHH01. The library contained 28 promoter variants and encompassed fivefold variation. The experimental pipeline allowed construction and measurement of expression levels of the library in just 4 days. This β-galactosidase provides a promising tool for engineering of aerobic, anaerobic, and thermophilic production organisms such as Geobacillus species.
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Shen X, Bao W, Yu W, Liang R, Nguyen B, Liu Y. An improved method with high sensitivity and low background in detecting low β-galactosidase expression in mouse embryos. PLoS One 2017; 12:e0176915. [PMID: 28475610 PMCID: PMC5419561 DOI: 10.1371/journal.pone.0176915] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 04/19/2017] [Indexed: 11/25/2022] Open
Abstract
LacZ is widely used as a reporter in studies of gene expression patterns. β-galactosidase, the product of LacZ gene, is usually detected by X-gal/FeCN staining. In X-gal/FeCN staining, β-galactosidase catalyzes X-gal to produce blue precipitates, which indicate the expression patterns of the gene of interest. A newer LacZ detection method using S-gal/TNBT is more sensitive but plagued by high background. Here, we describe an improved procedure that combines advantageous steps from the two methods. By comparing with X-gal/FeCN and S-gal/TNBT methods in detecting the expression patterns of miR-322/503 and miR-451 at a series of developmental stages, the improved method showed higher sensitivity and lower background. Thus, the improved method could be an alternative way of β-galactosidase staining in low gene expression situations.
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Affiliation(s)
- Xiaopeng Shen
- Department of Biology and Biochemistry, University of Houston, Houston, TX, United States of America
- The College of Life Science, Anhui Normal University, Anhui, China
- * E-mail: (YL); (XS)
| | - Wenjing Bao
- Department of Medicine, Liaoning University of Traditional Chinese Medicine, Shenyang, China
| | - Wei Yu
- Department of Biology and Biochemistry, University of Houston, Houston, TX, United States of America
| | - Rui Liang
- Department of Biology and Biochemistry, University of Houston, Houston, TX, United States of America
| | - Bao Nguyen
- Department of Biology and Biochemistry, University of Houston, Houston, TX, United States of America
| | - Yu Liu
- Department of Biology and Biochemistry, University of Houston, Houston, TX, United States of America
- * E-mail: (YL); (XS)
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Brg1 Enables Rapid Growth of the Early Embryo by Suppressing Genes That Regulate Apoptosis and Cell Growth Arrest. Mol Cell Biol 2016; 36:1990-2010. [PMID: 27185875 DOI: 10.1128/mcb.01101-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/02/2016] [Indexed: 11/20/2022] Open
Abstract
SWI/SNF (switching/sucrose nonfermenting)-dependent chromatin remodeling establishes coordinated gene expression programs during development, yet important functional details remain to be elucidated. We show that the Brg1 (Brahma-related gene 1; Smarca4) ATPase is globally expressed at high levels during postimplantation development and its conditional ablation, beginning at gastrulation, results in increased apoptosis, growth retardation, and, ultimately, embryonic death. Global gene expression analysis revealed that genes upregulated in Rosa26CreERT2; Brg1(flox/flox) embryos (here referred to as Brg1(d/d) embryos to describe embryos with deletion of the Brg1(flox/flox) alleles) negatively regulate cell cycle progression and cell growth. In addition, the p53 (Trp53) protein, which is virtually undetectable in early wild-type embryos, accumulated in the Brg1(d/d) embryos and activated the p53-dependent pathways. Using P19 cells, we show that Brg1 and CHD4 (chromodomain helicase DNA binding protein 4) coordinate to control target gene expression. Both proteins physically interact and show a substantial overlap of binding sites at chromatin-accessible regions adjacent to genes differentially expressed in the Brg1(d/d) embryos. Specifically, Brg1 deficiency results in reduced levels of the repressive histone H3 lysine K27 trimethylation (H3K27me3) histone mark and an increase in the amount of open chromatin at the regulatory region of the p53 and p21 (Cdkn1a) genes. These results provide insights into the mechanisms by which Brg1 functions, which is in part via the p53 program, to constrain gene expression and facilitate rapid embryonic growth.
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Trifonov S, Yamashita Y, Kase M, Maruyama M, Sugimoto T. Overview and assessment of the histochemical methods and reagents for the detection of β-galactosidase activity in transgenic animals. Anat Sci Int 2016; 91:56-67. [PMID: 26394634 PMCID: PMC4679788 DOI: 10.1007/s12565-015-0300-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 08/24/2015] [Indexed: 11/29/2022]
Abstract
Bacterial β-galactosidase is one of the most widely used reporter genes in experiments involving transgenic and knockout animals. In this review we discuss the current histochemical methods and available reagents to detect β-galactosidase activity. Different substrates are available, but the most commonly used is X-gal in combination with potassium ferri- and ferro-cyanide. The reaction produces a characteristic blue precipitate in the cells expressing β-galactosidase, and despite its efficiency in staining whole embryos, its detection on thin tissue sections is difficult. Salmon-gal is another substrate, which in combination with ferric and ferrous ions gives a reddish-pink precipitate. Its sensitivity for staining tissue sections is similar to that of X-gal. Combining X-gal or Salmon-gal with tetrazolium salts provides a faster and more sensitive reaction than traditional β-galactosidase histochemistry. Here, we compare the traditional β-galactosidase assay and the combination of X-gal or Salmon-gal with three tetrazolium salts: nitroblue tetrazolium, tetranitroblue tetrazolium and iodonitrotetrazolium. Based on an assessment of the sensitivity and specificity of the different combinations of substrates, we are proposing an optimized and enhanced method for β-galactosidase detection in histological sections of the transgenic mouse brain. Optimal staining was obtained with X-gal in combination with nitroblue tetrazolium, which provides a faster and more specific staining than the traditional X-gal combination with potassium ferri- and ferro-cyanide. We recommend the X-gal/nitroblue tetrazolium staining mixture as the first choice for the detection of β-galactosidase activity on histological sections. When faster results are needed, Salmon-gal/nitroblue tetrazolium should be considered as an alternative, while maintaining acceptable levels of noise.
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Affiliation(s)
- Stefan Trifonov
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan
| | - Yuji Yamashita
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan
| | - Masahiko Kase
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan
| | - Masato Maruyama
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan
| | - Tetsuo Sugimoto
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan.
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8
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Komatsu Y, Kishigami S, Mishina Y. In situ hybridization methods for mouse whole mounts and tissue sections with and without additional β-galactosidase staining. Methods Mol Biol 2014; 1092:1-15. [PMID: 24318810 DOI: 10.1007/978-1-60327-292-6_1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In situ hybridization is a powerful method for detecting endogenous mRNA sequences in morphologically preserved samples. We provide in situ hybridization methods, which are specifically optimized for mouse embryonic samples as whole mounts and section tissues. Additionally, β-Galactosidase (β-gal) is a popular reporter for detecting the expression of endogenous or exogenous genes. We reveal that 6-chloro-3-indoxyl-β-D-galactopyranoside (S-gal) is a more sensitive substrate for β-gal activity than 5-bromo-4-chloro-3-indolyl-β-D-galactoside (X-gal). S-gal is advantageous where β-gal activity is limited including early stage mouse embryos. As a result of the increased sensitivity as well as the color compatibility of S-gal, we successfully combined β-gal staining using S-gal with in situ hybridization using DIG-labeled probes in both whole mounts and sections.
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Affiliation(s)
- Yoshihiro Komatsu
- School of Biology-Oriented Science and Technology, Kinki University, Kinki, Japan
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9
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Sundararajan S, Wakamiya M, Behringer RR, Rivera-Pérez JA. A fast and sensitive alternative for β-galactosidase detection in mouse embryos. Development 2013; 139:4484-90. [PMID: 23132248 DOI: 10.1242/dev.078790] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The bacterial lacZ gene is widely used as a reporter in a myriad of mouse transgenic experiments. β-Galactosidase, encoded by lacZ, is usually detected using X-gal in combination with ferric and ferrous ions. This assay produces a blue indole precipitate that is easy to detect visually. Here, we show that Salmon-gal in combination with tetrazolium salts provides a more sensitive and faster staining reaction than the traditional β-galactosidase assay in mouse embryos. Using a combination of Salmon-gal and tetranitroblue tetrazolium, we were able to visualize the activity of β-galactosidase in embryos at stages when the customary X-gal reaction failed to detect staining. Our studies provide an enhanced alternative for β-galactosidase detection in expression and cell fate studies that use lacZ-based transgenic mouse lines.
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Affiliation(s)
- Sakthi Sundararajan
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, S7-228, Worcester, MA 01655, USA
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Bengtsson NE, Brown G, Scott EW, Walter GA. lacZ as a genetic reporter for real-time MRI. Magn Reson Med 2010; 63:745-53. [PMID: 20146234 DOI: 10.1002/mrm.22235] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Molecular imaging based on MRI is currently hampered by the lack of genetic reporters for in vivo imaging. We determined that the commercially available substrate S-Gal can be used to detect genetically engineered beta-galactosidase expressing cells by MRI. The effect and specificity of the reaction between beta-galactosidase and S-Gal on MRI contrast were determined both in vitro and in vivo. beta-galactosidase activity in the presence of S-Gal resulted in enhanced T(2) and T*(2) MR-contrast, which was amplified with increasing magnetic field strengths (4.7-17.6 T) in phantom studies. Using both lacZ(+) transgenic animals and lacZ(+) tissue transplants, we were able to detect labeled cells in live animals in real time. Similar to phantom studies, detection of the labeled cells/tissues in vivo was enhanced at high magnetic fields. These results demonstrate that the genetic reporter, lacZ, can be used as an in vivo marker gene using high-field-strength MRI.
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Affiliation(s)
- Niclas E Bengtsson
- Program in Stem Cell Biology and Regenerative Medicine, University of Florida, Gainesville, Florida 32610, USA
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Nomura-Kitabayashi A, Phoon CKL, Kishigami S, Rosenthal J, Yamauchi Y, Abe K, Yamamura KI, Samtani R, Lo CW, Mishina Y. Outflow tract cushions perform a critical valve-like function in the early embryonic heart requiring BMPRIA-mediated signaling in cardiac neural crest. Am J Physiol Heart Circ Physiol 2009; 297:H1617-28. [PMID: 19717734 DOI: 10.1152/ajpheart.00304.2009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Neural crest-specific ablation of BMP type IA receptor (BMPRIA) causes embryonic lethality by embryonic day (E) 12.5, and this was previously postulated to arise from a myocardial defect related to signaling by a small population of cardiac neural crest cells (cNCC) in the epicardium. However, as BMP signaling via cNCC is also required for proper development of the outflow tract cushions, precursors to the semilunar valves, a plausible alternate or additional hypothesis is that heart failure may result from an outflow tract cushion defect. To investigate whether the outflow tract cushions may serve as dynamic valves in regulating hemodynamic function in the early embryo, in this study we used noninvasive ultrasound biomicroscopy-Doppler imaging to quantitatively assess hemodynamic function in mouse embryos with P0-Cre transgene mediated neural crest ablation of Bmpr1a (P0 mutants). Similar to previous studies, the neural crest-deleted Bmpr1a P0 mutants died at approximately E12.5, exhibiting persistent truncus arteriosus, thinned myocardium, and congestive heart failure. Surprisingly, our ultrasound analyses showed normal contractile indices, heart rate, and atrioventricular conduction in the P0 mutants. However, reversed diastolic arterial blood flow was detected as early as E11.5, with cardiovascular insufficiency and death rapidly ensuing by E12.5. Quantitative computed tomography showed thinning of the outflow cushions, and this was associated with a marked reduction in cell proliferation. These results suggest BMP signaling to cNCC is required for growth of the outflow tract cushions. This study provides definitive evidence that the outflow cushions perform a valve-like function critical for survival of the early mouse embryo.
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Affiliation(s)
- Aya Nomura-Kitabayashi
- Laboratory of Reproductive and Developmental Toxicology, National Institutes of Environmental Health Science, National Institutes of Health, Research Triangle Park, North Carolina, USA
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Stoller JZ, Degenhardt KR, Huang L, Zhou DD, Lu MM, Epstein JA. Cre reporter mouse expressing a nuclear localized fusion of GFP and beta-galactosidase reveals new derivatives of Pax3-expressing precursors. Genesis 2008; 46:200-4. [PMID: 18395835 DOI: 10.1002/dvg.20384] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A new Cre-reporter strain of mouse has been developed that expresses a fusion protein derived from the lacZ gene fused to GFP with a nuclear localization signal. This construct is expressed from the ROSA26 locus upon Cre-mediated recombination that removes a loxP-flanked PGK-neo cassette, thus allowing for detection of Cre activity in all tissues. This reporter strain, which is similar to prior R26R and R26EGFP strains, has certain advantages related to the nuclear expression and the combined expression of both beta-galactosidase and GFP activities. We show that the use of this newly developed reporter line allows for enhanced resolution, detection and co-localization. Thus, we report a previously unrecognized subset of venous endothelial cells derived from Pax3 expressing precursors.
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O'Bryan MK, Takada S, Kennedy CL, Scott G, Harada SI, Ray MK, Dai Q, Wilhelm D, de Kretser DM, Eddy EM, Koopman P, Mishina Y. Sox8 is a critical regulator of adult Sertoli cell function and male fertility. Dev Biol 2008; 316:359-70. [PMID: 18342849 DOI: 10.1016/j.ydbio.2008.01.042] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 01/25/2008] [Accepted: 01/28/2008] [Indexed: 01/17/2023]
Abstract
Sox8 encodes a high-mobility group transcription factor that is widely expressed during development. Sox8, -9 and -10 form group E of the Sox gene family which has been implicated in several human developmental disorders. In contrast to other SoxE genes, the role of Sox8 is unclear and Sox8 mouse mutants reportedly showed only idiopathic weight loss and reduced bone density. The careful analysis of our Sox8 null mice, however, revealed a progressive male infertility phenotype. Sox8 null males only sporadically produced litters of reduced size at young ages. We have shown that SOX8 protein is a product of adult Sertoli cells and its elimination results in an age-dependent deregulation of spermatogenesis, characterized by sloughing of spermatocytes and round spermatids, spermiation failure and a progressive disorganization of the spermatogenic cycle, which resulted in the inappropriate placement and juxtaposition of germ cell types within the epithelium. Those sperm that did enter the epididymides displayed abnormal motility. These data show that SOX8 is a critical regulator of adult Sertoli cell function and is required for both its cytoarchitectural and paracrine interactions with germ cells.
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Affiliation(s)
- Moira K O'Bryan
- Monash Institute of Medical Research, Monash University, Melbourne, Australia.
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Lavado A, Lagutin OV, Oliver G. Six3 inactivation causes progressive caudalization and aberrant patterning of the mammalian diencephalon. Development 2008; 135:441-50. [PMID: 18094027 DOI: 10.1242/dev.010082] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The homeobox gene Six3 represses Wnt1 transcription. It is also required in the anterior neural plate for the development of the mammalian rostral forebrain. We have now determined that at the 15- to 17-somite stage, the prospective diencephalon is the most-anterior structure in the Six3-null brain, and Wnt1 expression is anteriorly expanded. Consequently, the brain caudalizes, and at the 22- to 24-somite stage, the prospective thalamic territory is the most-anterior structure. At around E11.0, the pretectum replaces this structure. Analysis of Six3;Wnt1 double-null mice revealed that Six3-mediated repression of Wnt1 is necessary for the formation of the rostral diencephalon and that Six3 activity is required for the formation of the telencephalon. These results provide insight into the mechanisms that establish anteroposterior identity in the developing mammalian brain.
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Affiliation(s)
- Alfonso Lavado
- Department of Genetics and Tumor Cell Biology, St Jude Children's Research Hospital, 332 N. Lauderdale, Memphis, TN 38105-2794, USA
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