RNAi Mediated Gene Knockdown and Transgenesis by Microinjection in the Necromenic Nematode Pristionchus pacificus

The overall goal of this procedure is to successfully transform foreign DNA and knock down gene function in Priyanka Pacificus nematodes. For transgenesis. Start by preparing the proper genomic DNA with compatible cohesive ends.

For RNA interference, synthesize the gene of interest using a double stranded RNA transcription kit. Then micro inject the PRIs DIANCA pacificus goads with the DNA or double stranded RNA. Screen, the F1 population for the selected marker phenotype in transgenesis and selected for the knockdown phenotype for RNA interference for transgenesis.

Continue to monitor results of F two transgenic worms to obtain results that show specific gene expressions using GFP reporter through fluorescence microscopy. Hi, I am Ray Hong, California State University of Northridge, and this demonstration will outline the steps for genetic manipulation in pristi specific nematodes. In emerging model organism performing RNAi and truss Genesis can answer key questions in developmental biology and behavior by characterizing gene functions and expressions.

Individuals new to this method will benefit from viewing how to place the worm on the injection pad and to inject the worm on the correct focal plane where the go nats are visible. Unlike gans goad SCA specific as goads cross each other dorsally and migrate eventually as the nematode develops from late J four into adults. In addition, genomic DNA digested with compatible restriction enzymes should be added to your transgenes and co injection marker to make your injection mix.

Jessica Single poin lab in my lab will demonstrate microinjection in PRIs case specific For transgenesis 3D NA Constructs are required for injection the dominant co injection marker. The target reporter transgene and genomic D-N-A-D-N-A constructs are digested with compatible restriction enzymes. The DNA constructs are collected using an ethanol precipitation protocol.Call.

The injection mixture is made to the concentrations listed in the table. Verify the pressure gauge settings of the nitrogen tank. Now load one to two microliters of injection mixture into the needle.

Place the needle in the microinjection manipulator. Break the needle tip by touching it slightly to an edge of a thinly pulled capillary tube placed on a slide and set it at an idle position. Now pour paraffin oil to cover the plate of J four young adult worms.

Pick a single worm and transfer it to an injection pad. Under the scope position the worm's gonad in the direction of the needle with the vulva away from the needle. Now lower the needle into position of the microscope view.

Bring the top gonad and the needle into the same focal plane. Gently poke the worm and pump in the injection mixture. Notice the eggs separating towards the distal tip indicative of a successful injection.

Reposition the needle to inject the lower gonad and repeat the injection. Since this gonad is under the gut, the spreading of the eggs will not be seen and therefore it's more difficult to gauge the success of the injection. However, post-injection, the worm should remain intact without protruding goads.

Replace the needle back in the idle position. Add a drop of M nine buffer to rescue the worm using some OP 50 bacteria on a pick. Touch the worm with the OP 50 such that it sticks.

Now transfer the worm onto a plate seated with 50 microliter spots of OP 50. Store the injected worms at 20 degrees Celsius for roughly four days to lay and grow F ones. Now screen the worms for the selected phenotype.

Pick single F ones with the observed phenotype to new seeded plate and store at 25 degrees Celsius. Finally, for transgenic lines, transfer single F twos into individual plates. Store subsequent generations at 20 degrees Celsius.

Manipulation of gene function at the organismal level by RNAi and transgenesis are key aspects of the Ppac pacificus model for evolutionary developmental biology compared to a wild type worm on the left, the stable F four PPR L three transgenic line results in a dominant roller that shows head neuron GFP expression. Conversely, this RNA I experiment generates PRL one mutants that exhibit complete knockdown of the rolling locomotion usually observed in the PRL one roller gain of function mutant TU 92 Once mastered, each injection can be completed in five minutes. It's important to remember that all F twos from independent F1 transgenic roll lines need to be singly picked to establish independent F two promi.

This is because we found GFP expression in to be highly variable among F two lines and transmission of the roller phenotype does not correlate with the G expression level.