Live observation of the oviposition process in Daphnia magna

Dohyong Lee; Ji Soo Nah; Jungbin Yoon; Won Kim; Kunsoo Rhee

doi:10.1371/journal.pone.0224388

Peer Review History

Original SubmissionJune 23, 2019
21 Aug 2019 Decision Letter - Gao-Feng Qiu, Editor PONE-D-19-15062 Live observation of the oviposition process in Daphnia magna PLOS ONE Dear Professor Rhee, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. We would appreciate receiving your revised manuscript by Oct 05 2019 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. 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Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: N/A Reviewer #2: N/A ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: While the scope is narrow, this descriptive morphological study revealed some interesting details concerning the process of egg deposition in daphnia. The following are detailed comments. 1. Some statements regarding basic daphnia biology are not accurate. Second paragraph of introduction, during parthenogenic reproduction, Daphnia magna can produce up to ~80 neonates depending on availability of food, ambient temperatures, age, etc. The range of 20-30 is too narrow. The authors are suggested to check with the classic review by Hebert (1978). Third paragraph of introduction, the brood interval is not fixed at 3 days but varies depending on several factors. 2. Third paragraph of results, each ephippium is known to contain two resting eggs. Why one resting egg? 3. The first sentence of the 4th paragraph needs to be backed up by references. So, according to this statement egg activation occurs before vitelline envelope formation? Also, what did the authors exactly mean by egg activation? 4. Second last sentence of the 4th paragraph in the results section, “to form after approximately 20 min” is not clear. It meant to be “approximately 20 min after egg deposition”? 5. Second sentence of the third paragraph in discussion, saying “arthropod eggs” is too general. Consider “the eggs of some arthropods”. Same paragraph, “The VE formed within…….”. 6. There does not appear to be good logic in the last 4 sentences of the 3rd paragraph in discussion. There is a lack of causal relationship between the three sentences concerning shrimp and prawn and the last sentence. What does a delay in VE formation observed in a shrimp and a prawn have anything to do with the speculation that egg activation in daphnia is triggered by squeezing in the oviduct? 7. References are not standardized. Each item should be in the same format and the Latin names italicized. Reviewer #2: This article studied the oviposition process and egg activation of Daphnia magna from the perspective of morphology. This study is not suitable for submission to this journal and is recommended for submission to professional morphology journals. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0224388.r001
Revision 1
4 Oct 2019 Author Response Reviewer #1: While the scope is narrow, this descriptive morphological study revealed some interesting details concerning the process of egg deposition in daphnia. The following are detailed comments. 1 Some statements regarding basic daphnia biology are not accurate. Second paragraph of introduction, during parthenogenic reproduction, Daphnia magna can produce up to ~80 neonates depending on availability of food, ambient temperatures, age, etc. The range of 20-30 is too narrow. The authors are suggested to check with the classic review by Hebert (1978). Third paragraph of introduction, the brood interval is not fixed at 3 days but varies depending on several factors. We are grateful of helpful comments of the reviewer. We carefully took a look at the review by Hebert (1978) and corrected as suggested. Ebert (2005) also indicated that an adult female may produce a clutch of eggs every 3 to 4 days until her death. 2. Third paragraph of results, each ephippium is known to contain two resting eggs. Why one resting egg? We understand that each ovary produce one resting egg. Since an ephippium originate from two ovaries, it contains two resting eggs. The text was corrected as suggested. 3. The first sentence of the 4th paragraph needs to be backed up by references. So, according to this statement egg activation occurs before vitelline envelope formation? Also, what did the authors exactly mean by egg activation? As suggested, we backed up the sentence with two references (Anderson, 1967; Masuda et al., 1991). The most critical event of egg activation may be the elevation of intracellular calcium levels (Horner and Wolfner, Dev Dyn 237:527-544, 2008). Egg activation in Drosophila is known to occur during ovulation (Kaneuchi et al., PNAS 112:791-796, 2015). Egg activation of shrimp was also reported during spawning and formation of vitelline envelope follows after egg activation (Pongtippatee-Taweepreda et al, 2004; Pongtippatee et al., 2012). VE formation is followed after egg activation (Anderson, 1967; Masuda et al., 1991). 4. Second last sentence of the 4th paragraph in the results section, “to form after approximately 20 min” is not clear. It meant to be “approximately 20 min after egg deposition”? I appreciate for your correction. We changed the sentence as suggested. 5. Second sentence of the third paragraph in discussion, saying “arthropod eggs” is too general. Consider “the eggs of some arthropods”. Same paragraph, “The VE formed within…….”. I appreciate for your careful reading. We changed the sentence as suggested. 6. There does not appear to be good logic in the last 4 sentences of the 3rd paragraph in discussion. There is a lack of causal relationship between the three sentences concerning shrimp and prawn and the last sentence. What does a delay in VE formation observed in a shrimp and a prawn have anything to do with the speculation that egg activation in daphnia is triggered by squeezing in the oviduct? It is likely that egg activation in Daphnia also precedes VE formation. We speculate that Daphnid eggs are activated during oviposition which is the most visible event prior to VE formation. In fact, Drosophila eggs are activated by pressure when they pass through the reproductive tract (Horner and Wolfner, 2008). We carefully rewrote the sentences to emphasize our points. 7. References are not standardized. Each item should be in the same format and the Latin names italicized. We formatted the whole manuscript, following strictly the instruction of Plos One. We also standardized the list of references as suggested. Reviewer #2: This article studied the oviposition process and egg activation of Daphnia magna from the perspective of morphology. This study is not suitable for submission to this journal and is recommended for submission to professional morphology journals. We admit that this manuscript is descriptive. However, our works provide an insight how a parthenogenic egg starts development after oviposition. It is known that developmental patterns of embryos in many species are already fixed in oocytes. For example, the anterior-posterior and dorsal-ventral axes of Drosophila embryos are determined during oogenesis. Even if Drosophila eggs pass through a tight reproductive track for ovulation, their cytoplasmic arrangement should not be disturbed. However, the oviposition pattern of the parthenogenic Daphnia egg does not allow us to imagine that the developmental axis are maintained during oviposition. What we observed is that the egg contents flow through a narrow egg canal. After oviposition, Daphnia eggs are known to follow a strict developmental pattern. Significance of this work may be that we raise a possibility that developmental axis of Daphnia may not be fixed during oogenesis but be established after oviposition. Since our observations provide an insight on a new way for developmental pattern formation, we believe that this manuscript brings a general interest in the field of animal development as well as Daphnia research. Attachments Attachment Submitted filename: response (2, Plos One).docx https://doi.org/10.1371/journal.pone.0224388.r002
14 Oct 2019 Decision Letter - Gao-Feng Qiu, Editor Live observation of the oviposition process in Daphnia magna PONE-D-19-15062R1 Dear Dr. Rhee, We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements. Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication. Shortly after the formal acceptance letter is sent, an invoice for payment will follow. To ensure an efficient production and billing process, please log into Editorial Manager at https://www.editorialmanager.com/pone/, click the "Update My Information" link at the top of the page, and update your user information. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, you must inform our press team as soon as possible and no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. With kind regards, Gao-Feng Qiu Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: N/A ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The authors responded to reviewers' comments and concerns pretty well. Couple of typos: 1. Page line 9 from top, "smaller than the case of" to "smaller than those for". 2. Page line 4 from bottom, "Daphnid" to "daphnid". ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No https://doi.org/10.1371/journal.pone.0224388.r003
Formally Accepted
22 Oct 2019 Acceptance Letter - Gao-Feng Qiu, Editor PONE-D-19-15062R1 Live observation of the oviposition process in Daphnia magna Dear Dr. Rhee: I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. For any other questions or concerns, please email plosone@plos.org. Thank you for submitting your work to PLOS ONE. With kind regards, PLOS ONE Editorial Office Staff on behalf of Prof. Gao-Feng Qiu Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0224388.r004

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