Drosophila spp., also known as fruit flies, are widely used in genetic research. Drosophila lines (e.g. flies with a particular mutation) can only be stored as live animals – they cannot be frozen and still remain viable. So to maintain the stocks, the live flies are manually transferred from an old vial to a new vial on a regular basis (every 1-2 weeks). Some Drosophila labs maintain hundreds or even thousands of individual lines and so maintenance of these lines can be very time consuming. A UC Santa Cruz Drosophila researcher has developed a simpler and more efficient method of transferring the flies that requires significantly less hands-on work.An earlier version of this invention has been patented and patent prosecution continues. However, additional improvements to hands-free Drosophila maintenance systems were still necessary. In particular, a device that could be fabricated by injection molding would be advantageous as would a device that could better facilitating labels of stocks and that can be more readily separated into individual components for shipping and study. 

Researchers at UCSF, funded in part by the Chan Zuckerberg Biohub, have generated a modular and effective CRISPRi system for the genetic dissection of non-model bacteria.

The inventors engineered a set of LbCas12a mutants through rational design and directed evolution. The engineered mutants can function as efficient genome editors with minimized trans-activity.

These are mice on the BALB/cAnNCrl background that lack functional STING protein. A 5 bp deletion (GCCTC; nucleotides 402-406 of NM_001289591.1) was introduced to exon 3 of the mouse Sting1 gene via CRISPR/Cas9 methodologies 

Gene targeted B6 strain mice in which the Klrk1 gene, which encodes the NKG2D immunoreceptor, is inactivated. On the C57Bl/6J genetic background.  Strain name: B6.Cg-Klrk1tm1Dhr  The inventors provided the first characterization of NKG2D-deficient mice, including evidence that NKG2D was not necessary for NK cell development but was critical for immunosurveillance of epithelial and lymphoid malignancies in two transgenic models of de novo tumorigenesis. In both models, the inventors detected NKG2D ligands on the tumor cell surface ex vivo, providing needed evidence for ligand expression by primary tumors.  Ligands for the NKG2D stimulatory receptor are frequently upregulated on tumor lines, rendering them sensitive to natural killer (NK) cells, but this mouse represents the first spontaneous cancer model addressing the role of NKG2D in tumor surveillance. 

Coronary atherosclerosis (a thickening of the arterial wall) is correlated to the occurrence of cardiac events; therefore, its correct and early diagnosis is paramount in the prevention and treatment of coronary artery disease. Researchers at UCI have developed an innovative method for assesses coronary artery stenosis and microvascular disease that is both accurate and non-invasive.

Prof. Manuela Martins-Green and colleagues from the University of California, Riverside have developed a mouse model for chronic wounds in db/db-/- diabetic mice. Wounds are considered chronic when the body is unable to properly facilitate every stage of the healing process due to Oxidative Stress (OS), which occurs when an imbalance of redox chemicals exists in the damaged tissues. To create the chronic  wounds the mice were treated with inhibitors of antioxidant enzymes (IAE) at the time of wounding only. The wounds were then covered with tegaderm membranes and allowed to become chronic. Control wounds were treated with placebo. Fig 1: Percent open wound area over time in wounds of C57BL/6 and db/db-/- mice.  

Modeling diseases as networks has helped simplify an otherwise complex web of multi‐cellular processes; however, an exclusive reliance on symmetric relationships in these networks overlooks the existence of disease continuum states and loses information relevant to pathogenesis and for the development of therapeutics. Network‐based analyses severely influenced by symmetric analyses have helped formalize Network Medicine as a field and deliver many successes, but drugs that can predictably re‐set the network in complex multi‐component diseases are yet to emerge.

Hypoxia-inducible factor 1-alpha is a transcriptional regulator of the adaptive response to hypoxia. When activated under hypoxic conditions, it can turn on over 40 genes involved in a variety of physiological activities. The dysregulation or alteration by mutation can lead to pathophysiology in areas of energy metabolism, cancer, cell survival and tumor invasion.

The TBX18 (T-box 18) transcription factor is a key player in the formation of the sinoatrial node (SAN) formation during embryonic development.

The Casp8 gene encodes a cysteinyl aspartate protease that is an essential part of the caspase activation cascade initiated by death receptors but it is also involved in preventing death receptors, Toll-like receptors TLR3 and TLR4 and T-cell receptors from inducing necroptosis. Caspase-8 also is essential for mouse development.

Insulin gene enhancer protein ISL-1 or ISL1 transcription factor, LIM/homeodomain is a highly conserved gene. It binds to insulin gene enhancer sequences and is necessary for heart development

Insulin gene enhancer protein ISL-1 or ISL1 transcription factor, LIM/homeodomain is a highly conserved gene (UniProtKB-P61371). It binds to insulin gene enhancer sequences and is necessary for heart development. In addition, it plays an essential role in the gene regulatory network crucial for retinal ganglion cell (RGC) differentiation.

The Wnt gene family is composed of a large number of secreted glycoproteins involved in a wide variety of cell interactions ranging from early to adult stage that play a role in morphogenesis, paterning and development. In contrast to the Wnt/β-catenin signaling pathway which most Wnt proteins signal through, Wnt-11 signals via the Wnt/JNK pathway. A recent study demonstrates that the expression of secreted factor Wnt-ll is elevated in several types of cancer, including colorectal cancer (2019 R. M. Kypta et al.)

Dishevelled (Dvl) proteins are important signaling components of both the canonical β-catenin/Wnt pathway, which controls cell proliferation and patterning, migration, differentiation, stem cell renewal and the planar cell polarity (PCP) pathway. Mammals share three Dishevelled (Dvl) family members and while the roles of Dvl1 and Dvl2 have been described previously, the functions of Dvl3 have remained an area of active research. The lack of Dvl3 in mice affects the formation of the heart, neural tube, and inner ear and that the defects in these tissues are much more severe when the mice are deficient in more than one Dvl family member, indicating redundant functions for these genes. Congenital heart disease affects approximately 75 in every 1,000 live human births, and approximately 30% of these diseases are due to disruptions in the outflow tract, the region affected in mice lacking Dvl genes.

The mouse Camp gene is an ortholog of the human gene CAMP, which encodes the precursor of cathelicidin antimicrobial peptide LL-37 (or CRAMP in mouse). Expressed mucosal epithelial cells, circulating neutrophils, and myeloid bone marrow cells, Camp is an essential part of the first line of defense against infection. In addition to antimicrobial activity, cathelicidin antimicrobial peptide plays a role in NK cell-mediated tumor growth suppression, and when secreted by neutrophils acts, as an attractant for monocytes, promoting wound healing or angiogenesis. Mouse CRAMP is implicated in adaptive immune response regulation and can interfere with TLR function via interactions with hyaluronan. Mice deficient in CRAMP are more susceptible to experimentally induced necrotic skin infection with Group A Streptococcus, urinary tract infection with uropathogenic E. coli, Pseudomonas aeruginosa infection, and meningococcal Neisseria meningitidis infection.

Miller–Dieker syndrome (MDS), or 17p13.3 deletion syndrome results in human neuronal migration disorders characterized by type 1 lissencephaly sequence (ILS), severe mental retardation and reduced life expectancy. The understanding of these syndromes is often incomplete and is the subject of active research. Researchers have demonstrated that the gene encoding 14-3-3ε (YWHAE), one of a family of ubiquitous phosphoserine/threonine–binding proteins, is always deleted in individuals with MDS. Mice deficient in Ywhae have defects in brain development and neuronal migration, similar to defects observed in mice heterozygous with respect to Pafah1b1.  Gene specific transcriptional activation or repression is regulated by a complex network of transcription factors designated the Myc/Max/Mad network. MNT (max binding protein) binds DNA and a heterodimer with MAX and represses transcription and acts as an antagonist of Myc-dependent transcriptional activation and cell growth. Described below are two mice strains that may be useful in studies of Miller-Dieker Lissencephaly Syndrome generated by the same researcher.

CAT2 is a membrane associated protein involved in the cellular uptake of cationic amino acids such as arginine, lysine and ornithine. CAT2 plays a regulatory role in the activation of macrophages. Arginine is a substrate for nitric oxide synthase (NOS) during the production of nitric oxide (NO). The release of NO by inflammatory cells contributes to the progression of diseases such as cancer, arthritis, inflammatory bowel disease, Crohn's disease, and atherosclerosis. CAT2 plays a role in controlling inflammation and IL-17 activation in an injury model of colitis.

Transgenic mouse models that develop spontaneous mammary adenocarcinomas have proven valuable in revealing molecular mechanisms underlying tumorigenesis and metastasis . Models target specific pathways depending on the transgene being expressed under the control of the mouse mammary tumor virus long terminal repeat (MMTV-LTR) or whey acid protein (WAP) mammary gland promoters and thereby replicate genetic defects in subsets of human tumors.

Ephrins and Eph receptor tyrosine kinases are cell-surface molecules that serve a multitude of functions in cell–cell communication in development, physiology, and disease.

The hyperpolarization activated nucleotide gated cation channel HCN4 is a pacemaker channel that is highly expressed in the sinoatrial node during development and in the adult. To better facilitate visualization of HCN4 expression, we generated mice with a nuclear localized (n) LacZ or H2BGFP knocked into the endogenous HCN4 locus and analyzed reporter expression in the heart during development.

These transgenic mice express an inducible version of cre recombinase mice under the direction of a Sox9 promoter. They are suitable for performing cre-recombination in pancreatic ductal cells and their progenitors.

Currently, alleles at multiple loci in the mouse genome must be combined by Mendelian genetics in crosses of animals to one another to produce a desired compound mutant genotype. For example, to combine homozygous mutations at two loci, animals that are heterozygous for each gene must be produced by breeding, and these are subsequently crossed to one another. Since the frequency of homozygosity for each allele is 1:4 the frequency of homozygosity for both genes is 1:16. Since the average litter of mice is approximately 10 pups, and the generation time from conception to reproductive age is about 3 months, this requires a substantial number of animals and time. With the addition of each new locus (three, four, etc), the cost measured in animals, time, and money increases exponentially. These factors increase substantially more if two or more loci are genetically linked, which requires rare recombination events to combine engineered alleles on the same chromosome. The CRISPR-Cas9 gene drive system stands to revolutionize rodent breeding. If each desired allele is encoded as a gene drive element that contains an sgRNA designed to target the same genomic location in the wild type homologous chromosome, each locus will be “driven” to homozygosity in the presence of Cas9. Therefore, in order to combine three alleles, for example, a mouse with one gene drive element (A) would be crossed to a mouse that encodes Cas9. Offspring of this cross would then be crossed to mice carrying gene drive element B, and these offspring would be crossed to mice carrying gene drive element C. In the presence of Cas9 at each generation, these gene drive elements at three distinct loci will be converted to homozygosity such that 50% of offspring, those that inherit Cas9, will be triple homozygous after three generations, even if they are genetically linked loci. A CRISPR-Cas9 mediated gene drive leverages the native cellular mechanism of homology directed repair to copy a desired allele from one chromosome to another. This process can convert a heterozygous genotype to homozygosity in a single generation. While CRISPR-Cas9 gene drives have been implemented in two species of insects, flies and mosquitos, it has not been reported in any non-insect animal species. 

Historically, the understanding of the development and pathophysiology of the human brain has been studied by examination of post-mortem and diseased specimens in conjunction with non-human primates and mouse models. The understanding of complex biological mechanisms is driven by advancement of techniques and new model systems and recent advances in stem technologies have contributed to the advancement of our knowledge of human neural development. Moreover, the reprograming of human somatic cells into induced pluripotent stem cells (iPSCs) which can be redirected to a specific cell fate has led to a breakthrough in neurobiology research. These findings have led to the generation of human brain organoids from IPSCs.

UCLA researchers in the Department of Physiology have developed a method of genetically silencing calcium signaling in cells and organisms for use in studying aberrant calcium signaling in disease.