We were approached by Cindy Lawley (Illumina Market Development) yesterday to see if we’d be able to participate in some product development. We agreed and need some geoduck DNA to send them, in case she’s able to get our species greenlighted for use.

Isolated DNA from ctenidia tissue from the same Panopea generosa individual used for the BGI sequencing efforts. Tissue was collected by Brent & Steven on 20150811.

Used the E.Z.N.A. Mollusc Kit (Omega) to isolate DNA from two separate 50mg pieces of ctenidia tissue according to the manufacturer’s protocol, with the following changes:

• Samples were homogenized with plastic, disposable pestle in 350μL of ML1 Buffer
• Incubated homogenate at 60C for 1hr
• No optional steps were used
• Performed three rounds of 24:1 chloroform:IAA treatment
• Eluted each in 50μL of Elution Buffer and pooled into a single sample

Quantified the DNA using the Qubit dsDNA BR Kit (Invitrogen). Used 1μL of DNA sample.

Concentration = 19.4ng/μL (Quant data is here [Google Sheet]: 20161221_gDNA_qubit_quant

Yield is low (~1.8μg), but have enough to satisfy the minimum of 1μg requested by Cindy Lawley.

Evaluated gDNA quality (i.e. integrity) by running ~250ng (12.5μL) of sample on 0.8% agarose, low-TAE gel stained with ethidium bromide.

Used 5μL of O’GeneRuler DNA Ladder Mix (ThermoFisher).

Results:

Overall, the sample looks good. Strong, high molecular weight band is present with minimal smearing. However, there is a smear in the ~500bp range. This is most likely residual RNA. This is surprsing since the E.Z.N.A Mollusc Kit includes n RNase step. Regardless, having intact, high molecular weight DNA is the important part for this project. Will prepare to send remainder (~1.5μg) of geoduck to Illumina with other requested samples.

The gel I ran earlier today looked real rough, due to the fact that I didn’t bother to equalize loading quantities of samples (I just loaded 1μL of all samples regardless of concentration). So, I’m repeating it using 100ng of DNA from all samples.

Additionally, this gel also includes C.gigas samples that Katie Lotterhos sent to us to see how they look.

Ran a 0.8% agarose, low-TAE gel, stained with ethidium bromide.

Results:

Look at that! The samples look MUCH nicer when they’re not overloaded and uniformly loaded!

Most have a prominent high molecular weight band (the band that’s closes to the top of the ladder, not the DNA visible in the wells). All exhibit smearing, but 2NF1 shows a weird accumulation of low molecular weight DNA.

Katie’s C.gigas samples (M1, M2, M3) look similar to the Olympia oyster gDNA, however her samples appear to have residual RNA in them (the fuzzy band ~500bp).

Will discuss with Steven which samples he wants to use for bisulfite treament and library construction.

Ran 1μL of each sample from yesterday’s DNA isolation on a 0.8% agarose, low-TAE gel, stained with ethidium bromide.

Results:

Since I didn’t load equal quantities of DNA, the intensities across the various samples is highly variable.

Those samples with high degree of smearing are also those with the highest concentrations. Thus, one would expect to be able to visualize a greater range of DNA sizes in a gel (because more DNA is present). Notice the samples with nice, high molecular weight bands and little smearing (1NF16, 1NF17). These are less than half the concentrations of all the samples that exhibit extensive smearing (2NF3, 2NF8, 1NF12). So, I think all samples will be fine for proceeding with bisulfite conversion and subsequent library construction.

However, I should re-run this gel using equalized DNA quantities for all samples…

Have three separate sets of geoduck & olympia oyster gDNA that need to be run on gels before sending to BGI for genome sequencing:

GEODUCK

• Phenol-chloroform cleanup from 20151124
• Mollusc kit extraction from 20151124
• DNAzol isolation from earlier today

OLYMPIA OYSTER

• Phenol-chloroform cleanup from 20151124
• Mollusc kit extraction from 20151124
• DNAzol isolation from earlier today

Ran 100ng of each sample on a 0.8% agarose 1x modified TAE gel w/EtBr.

Results:

All the samples from both sets appear to be overloaded. Overloading is generally seen as the streaking seen immediately above each band.

GEODUCK

Overall, the samples look pretty good. Sadly, the worst of the three (due to the most smearing – i.e. degradation) appears to be the DNA extracted using the E.Z.N.A. Mollusc Kit (Omega BioTek).

Also of note are the two bands present in the DNAzol sample. These bands are likely ribosomal RNA because I neglected to perform a RNase treatment during the extraction. Doh!

OLYMPIA OYSTER

None of them are particularly great. Just like the geoduck set, the worst of the three came from the E.Z.N.A Mollusc Kit (Omega BioTek).

Also, just like the geoduck set, there are two bands present in the DNAzol sample. These bands are likely ribosomal RNA because I neglected to perform a RNase treatment during the extraction. Doh!

The phenol-chloroform clean up sample is either jacked up or severely overloaded, based on the crazy streaking that’s present. However, this sample looked similar after the initial extraction on 20151113.

I will send these samples separately (i.e. will not pool them into single samples) to BGI to run QC and, hopefully, add them to the DNA they already have to complete the genome sequencing for these two projects.

I recently ran gDNA isolated for geoduck and Olympia oyster genome sequencing, as well as gDNA isolated from the Olympia oyster reciprocal transplant experiment out on a Bioanalyzer (Agilent) using the DNA 12000 chips. The results from the chip were a bit confusing and difficult to assess exactly what was going on with the DNA.

So, I ran 5μL of each of those samples on a 0.8% agarose 1x modified TAE gel w/EtBr to get a better look at how the samples actually looked.

Results:

Both the geoduck and the Olympia oyster samples for genome sequencing show intact, high molecular weight bands with some smearing (i.e. degradation). The oly sample looks a bit funky, most likely due to a gel anomaly. I’ll quantify these using a dye-based method for a more accurate quantification before sending off to BGI.

The Fidalgo 2SN samples all have intact, high molecular weight bands, but most of the samples show extensive smearing (i.e. degradation). However, sample 2SN 35 has no visible DNA at all.

Here’s a table highlighting the differences between the Fidalgo gDNA samples:

The fresh ctenidia samples were isolated by me on 20151021 and by Mrunmayee on 20151023. The frozen ctenidia samples were isolated by me on 20151103.

It’s interesting to note that Mrunmayee’s isolations appear to exhibit the least amount of degradation. Besides her handling the samples, the primary difference is that her samples were incubated in the buffer/Pro K solution O/N @ 37C, while my fresh samples were incubated @ 60C for 3hrs and my frozen samples were incubated @ 60C for 1hr. Overall, though, the frozen samples look the worst.

Finally, it’s also interesting to see that the two samples isolated using DNazol (geoduck and Olympia oyster genome samples) migrate more slowly than the remaining Olympia oyster samples which were isolated with the E.Z.N.A. Mollusc Kit.

Continuing with the RAD-seq library prep. Following the Meyer Lab 2bRAD protocol.

Prior to generating full-blown libraries, we needed to run a “test-scale” PCR to identify the minimum number of cycles needed to produce the intended product size (166bp).

I ran PCR reactions on a subset (Sample #: 2, 3, 17, & 30) of the 10 samples that I performed adaptor ligations on 20151029.

PCR reactions were set up on ice in 0.5mL PCR tubes.

Combined 12μL of master mix with 8μL of the ligation reaction from earlier today.

Cycling was performed on a PTC-200 (MJ Research) with a heated lid:

We’re following the “1/4 reduced representation” aspect of the protocol. As such, 5μL of each reaction was pulled immediately after the extension (72C – machine was paused) of cycles 12, 17, 22, & 27 in order to determine the ideal number of cycles to use. Also ran the ligation reactions (labeled “Ligations” on the gel below) of the samples as a pre-PCR comparison. Treated them the same as the PCR reactions: mixed 8μL of the ligation with 12μL of H2O, used 5μL of that mix to load on gel.

These samples were run on a 1x modified TAE 1.2% agarose gel (w/EtBr).

Results:

Gel image denoting sample numbers within each cycle number. Green arrow indicates the expected migration of our target band size of 166bp.

Looks like cycle 17 is the minimum cycle number with which we begin to see a consistent ~166bp band. Will continue on with the “prep-scale” PCR using 17 cycles.

Continuing with the RAD-seq library prep. Following the Meyer Lab 2bRAD protocol.

Prior to generating full-blown libraries, we needed to run a “test-scale” PCR to identify the minimum number of cycles needed to produce the intended product size (166bp).

I ran PCR reactions on a subset (Sample #: 2, 3, & 4) of the 10 samples that I performed adaptor ligations on Friday.

PCR reactions were set up on ice in 0.5mL PCR tubes.

Combined 12μL of master mix with 8μL of the ligation reaction from earlier today.

Cycling was performed on a PTC-200 (MJ Research) with a heated lid:

We’re following the “1/4 reduced representation” aspect of the protocol. As such, 5μL of each reaction was pulled immediately after the extension (72C – machine was paused) of cycles 12, 17, 22, & 27 in order to determine the ideal number of cycles to use. Also ran the ligation reactions (labeled “Ligations” on the gel below) of the samples as a pre-PCR comparison. Treated them the same as the PCR reactions: mixed 8μL of the ligation with 12μL of H2O, used 5μL of that mix to load on gel.

These samples were run on a 1x modified TAE 2% agarose gel (w/EtBr).

Results:

Test-scale PCR gel. Green arrow indicates desired band. The numbers below the headings indicate the sample number.

This looks pretty good. The green arrow on the gel indicates the desired band size (~166bp). Although difficult to see on this gel image, there is a gradient in band intensities across the cycles (band intensity increases as cycle number increases). Looks like we can use 12 cycles for our PCRs.

One other aspect of this gel that is very interesting is the ligations. The three ligation samples all show an intact high molecular weight band! This is very surprising, since the input gDNA from these three samples does not look this.

Yesterday’s test scale PCR failed to produce any bands in any samples (expected size of ~166bp). This is not particularly surprising, due to the level of degradation in these samples. As such, repeated the test scale PCR, but increased the number of cycles.

Following the Meyer Lab 2bRAD protocol.

I ran PCR reactions on a the same subset of samples as yesterday (Sample #: 4, 7, 14, & 30).

PCR reactions were set up on ice in 0.5mL PCR tubes.

Combined 12μL of master mix with 8μL of the ligation reaction from yesterday.

Cycling was performed on a PTC-200 (MJ Research) with a heated lid:

We’re following the “1/4 reduced representation” aspect of the protocol. As such, 5μL of each reaction was pulled immediately after the extension (72C – machine was paused) of cycles 27, 32, 37, & 42 in order to determine the ideal number of cycles to use. Also ran the ligation reactions (labelled “ligations” on the gel below) of two samples (samples #: 14 & 30) as a pre-PCR comparison.

These samples were run on a 1x modified TAE 2% agarose gel (w/EtBr).

Results:

NOTE: Today’s gel image was taken with a proper gel imager (yesterday’s gel image was captured with my phone). The 27 cycles appears similar to yesterday’s results, even though the bands are not visible on yesterdays’ gel, due to limitations of the phone’s camera sensitivity.

There are a number of bands visible on this gel.

The green arrow on the image identifies what I believe to be the proper size band (~160bp). This band is present in all four cycling groups and at similar intensities across cycling groups.

The two lower molecular weight bands are very likely primer dimers. The Meyer Lab Protocol indicates that primer dimers will likely be present at ~70bp, ~90bp, & ~133bp.

Since we’ve been following along with Katherine Silliman’s 2bRAD progress, here’s an image of her test scale PCR to compare to ours:

Katherine’s test scale PCR. Notice how much more prominent her bands are in all cycle groups, compared to my gel above.

Since this is my first foray into RAD-seq QC, I’m not certain whether or not our test scale PCRs indicate any level of success. I will consult with Katherine and Steven about what they think. Since we’re on a timeline, and we’re just testing the viability of this whole process, I suspect Steven will have me proceed and see how things turnout.

Continuing with the RAD-seq library prep. Following the Meyer Lab 2bRAD protocol.

Prior to generating full-blown libraries, we need to run a “test-scale” PCR to identify the minimum number of cycles needed to produce the intended product size (166bp).

I ran PCR reactions on a subset (Sample #: 4, 7, 14, & 30) of the 10 samples that I performed adaptor ligations on earlier today.

All components were stored on ice.

dNTPs – 1mM working stock was made

• 10μL dNTPs (10mM)
• 90μL NanoPure H2O

ILL-LIB1 & 2 – 10μM working stocks were made

• 10μL ILL-LIB1 or -LIB2 (100μM)
• 90μL NanoPure H2O

ILL-HT1 & 2 – 1μM working stocks were made

• 1μL ILL-HT1 or -HT2 (100μM)
• 99μL NanoPure H2O

ILL-BC1 – 1μM working stock was made

• 1μL ILL-BC1 (100μM)
• 99μL NanoPure H2O

PCR reactions were set up on ice in 0.5mL PCR tubes.

Combined 12μL of master mix with 8μL of the ligation reaction from earlier today.

Cycling was performed on a PTC-200 (MJ Research) with a heated lid:

We’re following the “1/4 reduced representation” aspect of the protocol. As such, 5μL of each reaction was pulled immediately after the extension (72C – machine was paused) of cycles 12, 17, 22, & 27 in order to determine the ideal number of cycles to use. Also ran the ligation reactions (labelled “Digests” on the gel below) of two samples (samples #: 4 & 7) as a pre-PCR comparison.

These samples were run on a 1x modified TAE 2% agarose gel (w/EtBr).

Results:

The results aren’t great. No band(s) visible in any samples at even the highest cycle number (27 cycles). Although, if you squint pretty hard, an extremely faint band might be visible in between the 100/200bp markers in the 27 cycles group.

Regardless, the PCRs will need to be repeated with an increased number of cycles. This is not terribly surprising, as the Meyer Lab protocol indicates that degraded samples will likely need a greater number of cycles than what they recommend and that cycle number will have to be determined empirically.

Ran a 0.8% agarose, 1x modified TAE gel (w/EtBr) with geoduck and Olympia oyster gDNA that was precipitated earlier today. Used 5μL of each sample (~500ng).

Results:

Geoduck gDNA on left. Oly gDNA on right.

Overall, the DNA still looks very good. Slight smearing (indicating slight degradation), but the high molecular weight band is very prominent. Will fill out the necessary BGI forms and ship samples out on Monday.